Mother gifts family home - in return for rent paid on different apartment

Hi there my elderly mother wishes to gift us the family home (or sell it and give us the cash proceeds). In return we will need to pay for her rent in a small 1 bed apartment. I understand that if she gifts us the family home (or the cash proceeds from the sale of it), and we "buy" her an apartment to live in, this will be caught under the pre owned asset charge regime. But if we pay for her monthly rent instead, will this also be subject to the pre owned asset charge/gift with reservation of benefit regime? My guess is (if we were to pay her rent), that gifting us the home will be under the pre owned asset rules, or gifting us the cash proceeds of the sale would be under the gift with reservation of benefit rules (as she still benefits from the cash), but there doesn't seem anything conclusive on the HMRC website with regards to this situation (where you pay for someones rent.) Furthermore, if it were caught by the POAT regime would the annual amount charged be to POAT be how much I could rent out the family apartment for post tax, or if the sales proceeds are given to me, how much interest I receive on the proceeds after tax? Or if it were caught by the GROB regime would the value of the benefit be the market value of the new apartment she rents? thanks

Hi,
Please contact the Inheritance Tax team for advice.
Inheritance Tax: general enquiries
Thank you.

Thank you