I'm not going to offer to repay my mom every time she does something for me
Do you think it is okay not to repay her?
Yes, I feel like it is, people should do things for you because of love.
Even if you don't want to, it is wrong not to pay your mother back when she's done something for you. If you never repay the offer she might eventually not want to do you any favors.
The good thing is I just want to do good things for my mom, but if I don't pay her back, who cares?
If you've discussed this with her and neither needs the money nor expects you to return it, that might be OK. But to just feel entitled to have her throw money at you is wrong.