The timing of Sarah Ferguson’s return to the UK, after seven months of living under the radar in other people’s houses across Europe and in the Gulf states, is no accident.My bomb-proof sources tell me the disgraced former Duchess of York was well aware that Prince Harry and Meghan Markle were plotting their own move back to Britain, despite a campaign of secrecy so effective that the public announcement came as a complete shock to almost everyone.In other words, Ferguson knew what was going on and she laid her own plans accordingly.How did she find out? It’s significant that, four weeks ago, younger daughter Princess Eugenie gave birth to her third child, Adelaide Elizabeth Annina Brooksbank. It seems certain Ferguson has visited Eugenie and husband Jack at their home in Portugal following the baby’s arrival, despite keeping out of view since she and ex-husband Andrew Mountbatten-Windsor were evicted from Windsor’s Royal Lodge in February.Indeed, well-placed sources suggest that at one stage she was pleading to be given a free run of the secluded Portuguese home, so she could come and go when she pleased. That was a request too far for the Brooksbanks, who have no wish to see their bolthole under siege from paparazzi.But Ferguson has been welcomed as a guest by her daughter – and so have the Sussexes. Possibly Meghan and Harry confided their plans to Eugenie, telling her they intended sending their two children, Archie and Lilibet, to private schools in the Cotswolds.More likely, I feel, is that Meghan revealed the plan to Ferguson herself. She has two sound reasons for doing so. First, both women have existed in a state of open warfare with the Palace machine for years. Very few people on the planet have personal experience of what that’s like, and both will benefit by sharing their notes.More than that, Meghan has long regarded Ferguson as an example of how it’s possible to exist half-in, half-out of the Royal Family, trading on title and tradition to make money, especially in the States. The disgraced former Duchess of York was well aware that Prince Harry and Meghan were plotting a move back to Britain – and laid her own plans accordingly, writes Andrew Lownie It is likely, says Lownie, that Meghan herself told Fergie of the family's planned move. She has long seen Ferguson as an example of how to exist as a half-in, half-out royalAll the time she was a duchess, Ferguson was able to get away with blatantly flouting the rules – flogging her smoothie-blenders on QVC, appearing in adverts for Ocean Spray cranberry juice, and promoting Weight Watchers, while still living in a Crown property and brazenly showing up in the Royal Box at Wimbledon or Ascot. Even if Meghan didn’t confide all her plans, she will have dropped enough hints to convince the older woman that this was a good moment to emerge from cover.It’s a general rule that, however insatiable the public’s appetite for royal gossip, there’s almost never room for more than one story at a time in the headlines.That’s why the Palace diary fixers work so assiduously to ensure royal engagements and announcements do not clash – and why there’s so much resentment among courtiers when Harry and Meghan crash the limelight by staging an unofficial royal tour in Africa or Australia. Ferguson knows how to make this work in her favour.All the public attention this week, and probably for most of September, will be on the Sussexes: where are they house-hunting; which schools have they favoured and, most intriguingly, how long is Meghan going to remain in the UK with her family before dashing back to California?That leaves limited media time for questions about where Ferguson is going to live and how she will pay the rent.Many have assumed she is spending the money left to her by her former boyfriend and sugar daddy, the F1 tycoon Paddy McNally, who died in July aged 88 – or, at least, borrowing money in anticipation of a bequest, once probate is granted.But I’m told this is not the case. Whatever income she has is coming from the Gulf states, from an unknown benefactor, in all likelihood a high-ranking member of a Middle Eastern royal family. McNally did help her out when she first became homeless, allowing her to stay at his home in Verbier, Switzerland, once known as ‘the Cocaine Castle’.Her welcome soon wore thin. Ferguson is not a woman to accept one gift without asking for more, as the world saw for itself when her money-grubbing email exchanges with billionaire financier and paedophile Jeffrey Epstein were published.McNally grew heartily sick of her, and apparently left her nothing at all in his multi-million pound will. This must have been a bitter blow and helps explain why she didn’t bother to attend his funeral in Wiltshire earlier this month, sending her daughter Beatrice instead.Yet reliable rumours suggest she has her sights set on a six-bedroom house in a gated community in the Home Counties, for a rent of £10,000 a month. And she appears ready to move in immediately, since the place undoubtedly comes fully furnished.She also has crates of personal possessions in a London storage unit, though reports that more furniture has been stored by Andrew at his Sandringham lodgings, the cramped and shabby Marsh Farm, are less likely to be true.Ferguson’s relationship with her ex-husband is, in fact, at a low ebb of mutual recrimination and distrust. He knows she has been peddling herself around TV production companies and publishers in the US, and she has already turned down a $1 million offer for an exclusive interview, in the hope of an even bigger payday. She has little left to lose – her reputation is in shreds.A tell-all memoir about her friendship with Epstein could command a colossal advance, if she is prepared to betray her ex-husband comprehensively.She must always have known what went on during his visits to Epstein’s homes and private island: the array of sex toys on display in every room and the photographs of naked, very young women on the walls were impossible to ignore, according to multiple witnesses.Of course she is mindful of the need not to incriminate herself further. She potentially faces new allegations about her relationship with Epstein with the likely unsealing of court documents in the libel case between Virginia Giuffre and Ghislaine Maxwell and release of further material under the Epstein Files Transparency Act in the coming weeks.So far she has not come forward to assist Thames Valley Police and other forces with their investigations into the former Prince Andrew and his alleged misconduct – allegations which he has steadfastly refuted.Silence will not be an option now she is returning to England. One obvious solution would be to seek a legal guarantee of indemnity, a promise that she will not be prosecuted. In return, she could tell the police everything she knows.This could be attractive to detectives who are beginning to fear that, however much they suspect Andrew Mountbatten-Windsor is guilty of both sexual and financial wrongdoing, amassing the evidence to prove it in court might be impossible.Sarah Ferguson could well be the witness they need to change that. This unexpected return to England is her own version of Finding Freedom... and her freedom could yet spell the end of her ex-husband’s.Entitled: The Rise And Fall Of The House Of York, the biography of Andrew Mountbatten-Windsor and Sarah Ferguson, by Andrew Lownie, is published by William Collins.