In a nutshell, SIL told me she's being kicked out by February due to landlord selling up and because of her being on housing benefit, it's harder to get a landlord to take her on. So, what she's doing is offering another 6K on top of the initial month's rent in advance, which will be hard for a landlord to let pass if it's his best offer.
Money is being borrowed by Nan.
DH and family know (common knowledge), that she's having to move by February.
DH did not know she was borrowing the £6K from his Nan. It came about that I told him because he wondered how she'd offered to move so quickly and I said "She's borrowing 6K from Nan to help move".
The day later DH told his Mum "By the way, if Molly asks for money don't give her any. She's getting 6K from Nan". Her reply was "there's nothing you can tell me I don't already know Micky
" I was given quite a stern look...
That same evening SIL came round with DN and was acting a bit off with me... not horrible but didn't seem as chatty.
How unreasonable was I to have told DH?
Should I have known to keep my mouth shut even though she didn't say "between you and me"?
I didn't think it was that big an issue at the time since she told me about the money like she was listing what was for Christmas dinner 