MIL giving husband money

AITA for telling MIL to stop randomly depositing cash in my husband's bank account? He makes almost 90k/year and can manage on his own. She has always done this and when he was in his early twenties she had her account linked to his and when his balance was low would transfer money to him so it took years for him to start becoming more financially responsible. She does this to have control and feel she is contributing because she's always been a shitty mom. I told her if she wanted to contribute she can deposit money into our kids' savings accounts. She blew up on me and apparently I'm just the worst for asking her to stay out of our financial business.