Where Sarah lives is entirely and completely her own decision. As we all know she lived in a huge mansion with Andrew purely for their own mutual convenience. If she doesn’t want to live in Norfolk in a five bedroom house with her ex, then don’t. The same with any granny flat her daughters may provide.
The world is wide. Sarah surely has a couple of million left out of all the millions of dollars she has earned over the years, and I’m sure she still has some links/contacts with people in London, Windsor, Europe, the ME or the US who would be willing to lease her a small apartment. She is now a free agent. Use that as an opportunity to start a new phase in her life.
What really is needed is for a full audit of Fergie's assets to be undertaken in order to see exactly what she owns. This would certainly separate her affairs from Andrew M-W. As you say, she has earned millions; she also seemed to be very good at keeping them - her staff were paid very badly, if at all - during one of her many financial crises, the Daily Telegraph disclosed that she came to agreements with many of them whereby they accepted a proportion of what they were owed. This I always thought was particularly nasty of Fergie, because she then carried on her usual round of holidays, parties and appearing in designer clothes. Incidentally, the Historian A.N. Wilson disclosed last month that all of Fergie's literary 'efforts' were in fact written by ghost writers who were paid pittances. At one stage, Fergie was earning considerably more than AM-W
To deal with some of the points raised above:
Fergie has never been made bankrupt [unfortunately in my view, because this would have forced the appointed official known as the 'Trustee in Bankruptcy' to investigate all her assets.]
Any items that are royal property are just that - not owned by Andrew [or Fergie]- on their loan a formal [for which read 'official' record of the loan] would have been made. Andrew would therefore find himself unable to retain from Royal Lodge anything that was 'owned' by either the Royal Collection or indeed by the Royal Family.
Any items that AM-W [and Fergie] received on royal tours as 'gifts' actually belong to the state, not AM-W and/ or Fergie.
AM-W certainly used to gift Fergie jewellery as presents - I have identified Cartier necklaces when she wore them; she also possesses the magnificent Tiara that she wore to her wedding - a present from HLM.
More intriguingly, Fergie owns (or perhaps owned!) El Pucará, the Argentine polo ranch she inherited from her mother. When Fergie received her divorce settlement from Andrew, the papers [including the reputable ones] claimed that Fergie gave half the money she received to her mother to 'save the ranch' which Mrs Barrantes was in danger of losing because of her own financial difficulties ['the apple does not fall very far from the tree' etc] I know that some of the land was sold to the Australian Kerry Packer who was a polo player. Mr Packer owned an adjacent estate. I would speculate that if the ranch is still in Fergie's possession, some of it might belong to her sister Jane, because I assume that Mrs Barrantes left El Pucara to both her daughters, although Fergie might have bought Jane's share out. Either way, it would not belong to AM-W
AM-W has apparently received an invitation to live in Bahrain. Could this be extended to Fergie as well? Even if she wanted to do so, Fergie might have difficulty in moving abroad - most countries in Western Europe would not want to host a reprobate like her.
If Fergie wishes to live in Windsor, she might be able to rent / lease one of the very much smaller cottages located in the Great Park. I am remined about Marina Ogilvy, who was able to do this even though she was very much persona non grata at the time. [It was then discovered that the rent was being paid by Social Security {British Welfare]
That aside, I am intrigued by photos today showing AM-W riding with a horse and a groom from Windsor Castle. I would have thought that he had to surrender these privileges.