I want to get my ex fired
Don't you think that's too much? Why do you want to get her fired?
She disrespected my parents and called them names
You are so understandably angry with your ex for being mean to your parents, but this is not something someone gets fired over. You need to get you and your parents away from this ex entirely. Leave town and never give out your new address to anyone.
What's wrong with making her life a living hell?
It's wrong because you will be retaliating against someone that will ruin her life, and that wasn't even close to what she has done to you and your parents. If you want apology from her then you can do that by communicating with her, and not causing her to lose her job in the process as that is going to be really cruel.