I can only echo what the others say about getting help with the legal side. There are numerous ways to get that in the UK. Now, is the good lady divorced yet, or merely separated? It sounds as if it is the latter, and that will require negotiation, but essentially the ex is required to provide for her.
Setting up a new household? Been there and done that, at second hand, after the fire in my parants’ house a decade ago. A quick and easy and very cheap way to get furnished is to go to a furniture reclaim store or big charity shop that does furniture. If she can find somebody with a van, you can get free furniture from the small ads - “buyer collects.”
Someone mentioned John Lewis. I gather that they have having big financial problems, I don’t know how that affects business from the customer’s point of view.
I do not recommend sending physical gifts. Anything over around US$50 will attract customs dues, and maybe require you to go across town to pay for it and collect it. You can of course just order something online and have it sent to her address, I do this fairly often.
Of course, the simple answer is just to send money. If she does all the buying, this avoids any possible duplication of purchases.