AITAH for giving my best friend some of my own personal money to buy gifts for his twin daughters birthday?

so I'm in a bit of an argument here with my wife and I think she's overreacting way too much but I need to know if I'm wrong here.

my best friend has 4 kids, a 16 year old girl a 14 year old boy and two 9 year old twin girls.

For 5 years now his son has been fighting cancer bravely but unfortunately he's losing, right now he's terminal and in stage 4 and according to his doctors and oncologist team he has less than a year left and looking at the kid yea I believe that, and it really hurts because he's just an innocent kid and it's so unfair. but as a result my friend and his wife are financially struggling because of all the medical debt, to the point their oldest daughter is working and supporting herself.

my friend has always been a proud man who doesn't take help from anyone so even thought I've offered hundreds of times to help he refuses every time, so when a few days ago he came and asked me for help I immediately said yes, his twin girl's birthday is in a couple of days and he wants to get them something nice because he feels like he's overlooked them for years and he says he wants to get them both new phones since theirs are so old now and so I gave him a thousand bucks and he got them both new phones.

I didn't really ask my wife for permission because he never asks for help and I took the money out of my own personal account and not our shared family account but she still has a problem with that because that money should go to our own kids and family according to her but it's my own personal account, she also has her own account and money that she does what she wants with so I really don't see her point.

it's not like we're actively fighting about it and that we're getting divorced or anything like that but she's upset about it.

was i wrong here?