My NMom tried this. I was 17 when I moved out for college and she demanded that I get a bank account with her name on it so she could "access" my funds "if needed". I said "no" and my SO helped me get a bank account with only my name on it. I was dubbed "greedy and selfish". Then, my NMom demanded that I "sign over" my work study paychecks to her. At this point, she'd already stolen $1K in high school graduation money/checks, so I had zero money starting school. I needed my meager work study checks to pay for incidentals for school, so I told her "no". Again, I was "greedy and selfish". She stole my first credit card during one of my weekends home and maxed it out, necessitating that I take on a second job to afford those payments (I found out about the credit card when I intercepted a bill during winter break--she'd had a stroke and almost died and I was getting her mail and saw that she'd managed to change the billing address on my card). Once she knew I was working a second job, she demanded the entire paycheck from that, knowing I was now working 40 hours a week and going to school full-time to pay for the financial damage she'd done to me. She accused me of "making up" direct deposit to keep my money from her. She was a fan of saying "It's all one, big pot!" in reference to money, but I was usually the only person contributing to this pot. Finally I told her to never mention money to me again because as far as she was concerned, there wasn't any. I told her that we all were on a sinking ship and there was one life preserver and it could only save one person and I was taking it. I told her I wasn't responsible for saving her or the rest of the family, I had to take care of myself (I was putting myself through school with zero help and I barely afforded it). I, of course, was the worst person ever for standing up for myself. After she knew she couldn't get money from me, she opened up credit cards in my GCBrother's name and years later tried to talk me and all of my siblings into taking out a large limit credit card, cashing it out, giving her half the proceeds, then declare bankruptcy. She proposed this to me when I'd recently gotten married and was trying to buy a house with my SO and again told me how I was the "worst daughter ever" for telling her "no".

The only thing that really helped in dealing with my NMom was moving to another state--I wasn't the easiest resource to exploit.

As soon as humanly possible, OP, get out. You'll never be your own person to those people, you're only an extension of themselves; a resource to exploit. They will use your lack of money to control you and to leave you with no options. You need to save yourself, OP. Start squirreling away whatever you can and do what you can to get out. Good luck.