Aibu to get involved and stop my sister (Anna) from buying her son (my nephew-Brian) the house next door?
Anna is a very strong character, single parent for many years but now has a lovely partner, but she wears the trousers in everything (and did so when we were growing up, very driven, confident and wants what she wants)
Brian (going into year 9, so 13 nearly 14) is the polar opposite, lovely quiet kid but prone to anxiety, worries more than normal but certainly not crippling, attends school doing well. Has a select group of friends that Anna approves of but isn't allowed to socialise freely, isn't allowed down the park or beach etc only allowed around approved households or when she is with him. Our parents have mentioned that Brian needs more freedom but Anna disagrees.
Now the issue, I've agreed (a long time ago, but more than happy to do so) to put a deposit down on a house, which will be rented out until Brian is old enough to live there. The money is from a house sale elsewhere in the country and I now have the funds.
I have found a great house in the same area but Anna has been talking to the neighbours and has found out they are planning on selling and wants to buy this house. I feel this will become an extension of Anna's house and that Brian won't actually ever be able to move out. Anna says that his anxiety means that he won't be able to live apart from her, but I feel she smothers him.
AIBU to get involved, and I should let Anna buy the house next door or
AINBU and it is reasonable to not release the funds so that Brian can have a place nearby but not next door