Angelina Jolie looks blissfully happy. But are health fears troubling her paradise?

Never one to be upstaged, Angelina Jolie spent much of Sunday evening submitting herself to the sort of intensive ministrations from a small army of stylists, hairdressers and make-up artists that might seem a touch excessive even on one of her big budget movies.

The results were, unsurprisingly, traffic-stopping as she glided up the red carpet on the arm of lover Brad Pitt for an awards ceremony in Hollywood.

Not least because her billowing Hermes gown did an inadequate job of covering the "baby bump" that - if reports in the U.S. are correct - contains twins.

Her glittering display at the Screen Actors Guild Awards was, however, a marked transformation from her appearance earlier at the couple's Malibu home.

She is said to have spent the day in tears as she, Pitt, her actor brother James Haven and her four children commemorated the anniversary of her mother's death.

This was a manifestly different Angelina from her date with photographers the same evening. Make-up free, visibly shrunken and pale, friends say she spent the day reading poems and looking at pictures of Marcheline Bertrand, her actress mother who died of cancer a year ago.

An American source told the Mail last night: "It was a sad day, but Angelina knows her mother would have wanted her to carry on working and this was a big event."

As a bonus, the occasion afforded the couple the chance to put on a loved-up display for the cameras as they giggled and canoodled at their table.

One U.S. magazine reported last week that the couple are "ecstatic" after learning that they are expecting twins to add to their three adopted children and a biological daughter.

Certainly, there did appear to be the telltale signs of a tummy beneath Angelina's floor-length frock and she appeared oddly buxom given her slight arms.

What is undeniably true is that she has been trying for a child for several months. In September friends revealed doctors had advised her to put on weight if she wanted to get pregnant.

At the same time the couple are said to be planning to adopt a girl in New Orleans left orphaned by Hurricane Katrina to add to her rainbow family of adopted children (the couple already have sons Maddox, six, a Cambodian, and Vietnamese Pax, three, plus daughter Zahara, two, as well as Shiloh).

The move to adopt in the U.S. comes after Angelina is said to have been left heartbroken when her attempts to adopt another baby from Ethiopia were turned down eight weeks ago, after African authorities decided to crack down on foreign adoptions.

The decision came as it surfaced that, while Miss Jolie had publicly stated that Zahara was an orphan whose mother had died of Aids, the child's mother is, in fact, alive and - unbeknown to the famous couple - been the subject of a campaign of threats and intimidation from the local man who arranged the adoption.

But those around her are convinced that having a pregnancy to focus on couldn't be more timely for the actress.

Many in her circle had become concerned in recent months about her health as her weight plummeted worryingly to below seven stone. Her actor brother James went public over his own concerns, telling a magazine: "Angelina's life changed after she visited Ethiopia. Whenever she's there, there's often no food for her and she goes without.

"It's hard for her to sit in an expensive restaurant and order freely. She feels guilty about what she eats compared with so many starving people whom she wants to help."

All of which is perturbing, particularly when, as she continued to lose weight, Angelina was telling friends that her and Brad, 44, were trying for a baby.

Meanwhile, rumours have abounded in Hollywood in recent weeks that she collapsed twice on the set of her latest movie - Clint Eastwood's The Changeling (which might, of course, be explained by her early pregnancy).

She is also said recently to have confessed to being "depressed" about what she sees as her lack of progress in solving world hunger.

Another reason to celebrate her pregnancy is the positive effect on her relationship with Pitt, who is reported to have tired of her insistence on trailing their children around the Third World on her charitable missions.

Just weeks ago he was allegedly telling his family that his three-year relationship with Miss Jolie was so troubled he was considering applying for joint custody of the children.

But they quelled the gossip by putting on an over-the-top display of affection this month at the Critics' Choice awards in California. Then, as on Sunday, Angelina gave every impression of being a woman in love.

But, this being Tinseltown, some remain unconvinced, not least because their attempts to silence the chatter come at the same time as Brad is said to be preparing to put his acting career on hold to run for political office.

Sources in the Democratic Party say he has been approached to run for mayor of New Orleans, where he has set up his own foundation to build homes for the victims of Hurricane Katrina.

The break-up of another relationship so soon after his divorce from his first wife Jennifer Aniston (Pitt left the Friends actress after meeting Miss Jolie on the set of Mr & Mrs Smith in 2005) could hamper help his chances of election in two years' time.

His decision to follow fellow actor Arnold Schwarzenegger into politics would certainly explain the couple's decision to buy a £2million home in the disaster-hit Louisiana city after announcing that they are quitting LA and their Malibu mansion.

It is all part, say insiders, of the actor's attempts to distance himself from his reputation as a motorbike riding good-time guy and cement his reinvention as a man of the people.

He has hired his own "philanthropic adviser", Trevor Neilsen, who worked for President Clinton's Washington administration, to boost his humanitarian credentials and set up his own "Make It Right" campaign to build ecohomes in New Orleans' Ninth Ward, which was hardest hit by the floods.

But the family's relocation to the city's French Quarter has not been without its problems for the couple. Friends say life has become intolerable because they are mobbed by hordes of gawping locals wherever they go.

One source told the Mail: "It's bad enough in LA with the paparazzi, but at least in California there are loads of celebrities, and people leave you alone. But in New Orleans they are the only stars among a lot of very poor people who have never seen anything like them. The whole situation is beyond a joke."

An illustration of the goldfish bowl lifestyle the couple and their children have come to endure came on Boxing Day when Pitt drove Angelina and the children to a drive-through burger bar in a working-class neighbourhood after an afternoon at the cinema.

Soon the couple's white people carrier was surrounded by an mob of locals all attempting to take pictures with their mobile.

Eventually a bodyguard - part of a security team which always travels with them - was forced to confront the crowd and ask them to back off for the sake of the couple's scared children.

Despite the inconvenience, being visible on the streets will do no harm to Brad's bid for power (nor will the PR of adopting a New Orleans orphan). However Pitt, who took on his charitable causes after meeting Angelina, has not turned his back completely on his film star lifestyle.

As a refuge from his mercy missions to New Orleans, he has taken over a £50,000-a-month lease in Manhattan's ultra-glamorous Waldorf Towers.

He is said to retreat there for some "Brad Time" away from his new family. The star is said to be exhausted because he is expected by his lover to take over the bulk of child care, while she continues her filming schedule.

Associates say Pitt is tasked with getting the children up for school, so Angelina can have a lie-in. She also demands quiet while she is reading and recently left him alone with their brood, while she checked into a Beverly Hills hotel suite for several days.

At the same time she is said to have only half-joked to friends that Brad has not been able to keep up with the reams of UN briefing papers she insists they both read because he spends too much time having his hair lightened.

Nor has he been able to give up the boys' toys to which, like his taste for cigarettes, he remains addicted.

When he has found time to take a break from looking after the children, Pitt has been having helicopter lessons and has just taken his private pilot's exam to fly his own plane.

At Christmas he also added a 165mph Yamaha to his collection of motorbikes. They have come in useful. After one row during an ill-fated holiday to France in September, he is said to have ridden one of his motorcycles from the chateau they were renting in the Dordogne all the way to Berlin.

But their touchy-feely performance at the weekend would suggest they have put their problems behind them.

Angelina is also said to be keen to reconcile with her actor father Jon Voight after a six-year feud. Voight, who walked out on her mother when she was six months' old, was cut off by Angelina after he begged his daughter to seek help for her "serious emotional problems" on a TV show in 2002.

But, after Voight publicly lauding her humanitarian work, she is said to have called him on Christmas Day and told him she was prepared to try to repair their relationship.

With those rumours that she is expecting twins, perhaps Angelina feels it is time her ever-increasing brood got to know their grandfather.