My MIL has helped SIL buy a bigger house. On the proviso that's she live in part of the house. I've not seen it yet but it was mine and DH's understanding that MIL would have two bedrooms in her part of the house so our DC - her grandchildren could visit.
MIL is keeping her flat but moving in with SIL.
When DH went to pick up MIL it turned out her part of the property only has one bedroom.
SIL has two DC and their bit has three bedrooms - the fifth bedroom is going to be rented out so they can pay the mortgage.
Thing is MIL gave them a few hundred thousand £s so she could live there.
It's not as if we hardly spend time with MIL. DH myself and our DC often go to see her - several times a year.
Annoyed but knew this would happen...