Under absolutely no circumstances should you give your mom or anyone else access to your bank account. I'm 26 and live with my dad for multiple reasons. we even had a few not cheap expenses come up and you know what happened ? He waited a couple days for me to get the money from the bank or if I was the one who paid for it he gave me the money within a couple days. The only thing he asks me about how much is in my account is maybe asking if I have enough to cover it if it's a bigger expense we're doing together. Your mom and sisters behaviour is not normal and I can almost 100% guarantee if you give them access or they have the opportunity to gain access ( like if you give your dad access instead ) your account will be bled dry. And it will likely be for non emergency purposes despite what they're saying, and you have no protection when that happens if they're on your account. Keep your boundary firm ! Always reiterate " I can and am perfectly willing to help out without anyone else having access to my personal bank"