while true, the fact the mother lied to her, and acted in a way that completely destroyed her confidence on herself and her capabilities, even for stuff outside the supernatural, remain. She may have had good intentions, but good intention doesn't prevent abuse (even by neglect). And in this case, the mother execution for these intention seems lacking.
The road to hell is paved by good intentions is a proverb for a reason
I don't think it's that simple, just like anything in this series. It's also tied to the theory that her mom had a power overflow, which killed her dad, which could be totally wrong in the end!
Her confidence is tied to her powers. If her confidence balloons, her powers expand,
she loses control, and people around her die. It's a classic conundrum that many stories have tried to answer - is it okay to abuse one person if it keeps the rest of society safe? And if it's not, can you stomach having the blood of everyone else you know on your hands to ensure the happiness of one person?
The only thing that could have been done differently is Jedi-style training to manage one's emotions, but that also takes away the ability to have a normal life. Mom is likely torn between an impossible choice of giving her daughter a normal life via "abuse" or teaching her to manage her monstrous powers and destroying her humanity, making her just like her mother.