I am so sorry that you have a mom like that. she is pathetic and I pity her. You do not have to pay her back - Ever. A minor is not responsible for any debts or agreements. And, even an adult is only responsible for debts for things they agreed to pay as an adult. Life just doesn't work that way for parents. You don't pay it back - You pay it forward by taking care of your children in the future. You cannot change your mom. Be prepared to move out and take care of yourself when you can. Don't ever let her guilt you into agreeing to "pay her back."

charge her for all the joy you have brought her plus any chores

give her a bill for the cost of therapy to help you cope with her crappiness

that reminds me of my boyfriend's mom, total bitch move. why have kids then if you don't want to really spend money on them in the first place?

I am an attorney and BY LAW, she can not make you pay her back for any of the required necessities of your upbringing. You can even report her, if she does so within six months after your legal birthday, for child abuse to the CPA. Have a nice day.

If I were you I wouldn't talk to her at all when I'm an adult

remind her that you will pick the nursing home for her when the time comes...

"Sure, OK, but you do realise that means I can't afford kids of my own, right? Oh, you want grandchildren? Tough."

that sounds like freakin Matilda

it's clearly a joke