My mentor that led me into this hobby had a work around to this problem. He let his wife know that he kept $500 a month in cash for daily stuff like coffee, happy hours, and even incidental family purchases at the convenience or grocery store. Keep in mind sessions were like $200 back then, so he'd still have $100 if something really did come up like a "pick up some milk" call after sessioning twice in a month. Twice a month was pretty much his limit anyways since he had kids and an RN for a wife.
I've also thought about taking short side gigs on Fiverr or the like for $100-$300 a pop just to possibly break even on sessions. I'm too busy as is but it might work for you if you set up a bank account for yourself, especially at a credit union that has no minimum balance requirement.