The astonishing conversion of the Aitken girls

The secret wedding of Jonathan Aitken's daughter is the latest twist in their family's remarkable saga

Not many people loved Jonathan Aitken when he was sent to prison in 1999 for perjury and perverting the course of justice, but among the few that did was his 18-year-old daughter Alexandra, who looked on from the viewing gallery with the rest of her famil.

Her father may have been the "Commons Casanova," but it seems that Alexandra – or Ali – Aitken, at least, is destined for a more settled fate. Pictures published in this week's Hello magazine show 30-year-old Ms Aitken clad in white robes and aturban at her wedding to Inderjot Singh, a committed Sikh whom she met while she was travelling in India.

News of the former it-girl's wedding has come as a surprise to her family and friends; her father was informed of it only a few days before, and only her twin sister Victoria was permitted to attend. "It was agreed that I would go out there shortly after," explains Jonathan Aitken. "I am, of course, very happy for her."

It is the latest twist in the lives of the three Aitken sisters: Alexandra, her twin sister Victoria, and their half-sister Petrina Khashoggi – the latter's position in the family became clear only when she was 18 and a DNA test revealed that she was conceived during an affair between Aitken and Soraya Khashoggi, the ex-wife of the millionaire arms dealer Adnan Khashoggi. Ali Aitken has "never exactly been a PG Tips kind of girl", as one commentator put it. She has been many things: a model, a failing actress, a writer, and a somewhat-unconventional sculptress (emailing friends asking them to post her their eyelashes, with which to make a model).

She grew up in a life of privilege. With their father serving as a Cabinet minister for much of their early life, Alexandra and Victoria enjoyed the double luxury of an imposing townhouse in Westminster and a home in Kent. Their mother, the glamorous Lolicia Aitken, sent them to separate schools in an attempt to encourage their individuality. Alexandra went to King's Canterbury, while Victoria enrolled at Switzerland's exclusive Aiglon College before returning to board at Rugby School. When home for the holidays, the girls enjoyed the luxury of a live-in staff, including butler.

Their father's trial soon put an end to all that. Out of a job and with legal costs of £2.4m, Aitken was declared bankrupt. When he was dispatched to Belmarsh high-security prison, the bailiffs wasted little time. Many of the family's possessions were seized, and their two homes promptly sold.

Victoria, dragged into the public eye after giving evidence for her father, swiftly swapped the UK for life in the US. Her mother, meanwhile, moved to Switzerland, shifting between Zürich, Monte Carlo, Paris, New York and Tibet, unable to return to the UK for fear of being charged with perverting the course of justice.

Alexandra remained in London, carving out a new identity as a socialite. She attended parties, contributed to Tatler, and became part of the early-noughties Sloaney set which also included Lady Victoria Hervey and Tara Palmer-Tomkinson. Aged 21, along with Kashoggi, she posed naked in GQ magazine, revelling in her "posh totty" status.

And then, in 2002, things changed. In the first of her reinventions, Alexandra declared herself done with parties. Gone were the champagne flutes, and in their place the earnest insistence that she all she wanted was to be a serious actress. Surreptitious sniggers were silenced, temporarily, after she won a part in the adaptation of Ian McEwan's Atonement. When it was revealed that she contributed only two lines ("refrigerator magnate", infamously), those titters returned. Eventually, she left London, moving to Hollywood to offer psychic readings ("the world is going to get faster", she explained in a workshop titled "Accessing Time Portals to Abundance") and teach yoga.

If acting didn't pan out for Alexandra, Victoria's creative aspirations fared little better. Her contribution to rap music remains the stuff of legend. Initially poised to follow her father into politics – she enrolled at Washington DC's prestigious Georgetown University, and is said to have encouraged Euan Blair in his internship with Republican congressman David Dreier – an appearance on the ITV documentary Young, Posh and Loaded led to the beginning of an ill-fated music career.

Under the tutelage of the producer Larry Dvoskin, and styling herself as "Jenny from the Yacht", Victoria released songs detailing her move from "riches to rags". "Living off daddy's plastic was so fantastic," she chanted in one self-penned tune. "Just got a j-o-b, what a misery."

Long after her sister abandoned her film career, Victoria continued her attempts to enter the music business. Rap has since been replaced with a preference for dance music; alas, she remains off the books of any labels. But it is Khashoggi's whose tale has been the most tumultuous. While the twins embraced the news of their shared paternity with Khashoggi enthusiastically, Khashoggi was, claimed Alexandra at the time, more reticent.

Despite a relatively successful career as a model – she was on the elite Storm model agency's books – Khashoggi struggled with depression and addiction. In 2001, she was admitted to Surrey's genteel rehab clinic, Farm Place, complaining of "too much partying". While a friend footed the £2,000-a-week bill, Khashoggi recovered from her troubles. Three years later, however, she entered rehab for a second time – this time for love addiction. Who'd want to be the offspring of someone famous?

In India, Alexandra is over the moon with married life. She has adopted the moniker "Harvinder", and plans to remain in the country to start a family – an unconventional life plan, but one that has received her father's blessing. "Honestly, I'm just happy to see her so happy," Jonathan Aitken insisted yesterday. "It's really wonderful."

The full interview appears in the current edition of Hello! magazine