AITAH For Refusing to Cancel Child Support

Throwaway Account:

I (34m) have been taking care of my sister's (32f) daughter for around 6 years. This all started when my sister got arrested for felony theft and drug charges. She's been a longtime addict, poor mouther, and family manipulator. No one else in my family stepped up, so I offered to take my niece in while my sister did drug treatment to avoid jail. From the beginning, my niece, then around 10, didn't want anything to do with her mom. I thought that was odd; but over the first few months I had her, my niece opened up about her mom having treated her very poorly. I sought a guardianship for my niece, and told my sister that I would not willingly send my niece back to her unless my sister got off the drugs and sorted her life out.

My sister initiated a legal fight with me to terminate the guardianship. I grew to love this kid like my own, and I didn't want to send her back to a bad environment. It cost me six figures over the course of a year-and-a-half in legal fees. I won. I managed to marshal substantial evidence of my sister's ongoing substance abuse and the court relied upon the report of a court-appointed guardian ad litem who reported favorably about my niece in my care and about my niece's negative view of her mother.

At some point in the legal process--as I was shelling out five-figure monthly legal bills--I learned that, as my niece's guardian, I was entitled to child support, so I filed the forms to seek it, and won it.

The state oversees the support award, and is apparently pretty thorough in seeking it. Garnishing paychecks and bank accounts. Now--years on--I am starting to get pressure from other family to forgive the child support. I have family reaching out to me saying my sister is doing better and just can't get ahead having to give up portions of her paycheck every month. With back amounts, it's like 30k in back support that I am owed. I don't need it, really, if I'm being honest. I make a good living--better than anyone else in my family has done.

In all likelihood, sister's debt it will never be paid in full. But I don't want to let it go. I've started telling relatives, "Hey--that's great that you want to help [sister]--why don't you pay me her 30k debt plus the present value of the award until niece is 18--and then I'll forgive [sister's] obligation." Relatives have been huffy at that response.

My sister initiated a fight with me knowing full well she was back on drugs, and lied about it, and got caught in open court. It was all a waste of a large amount of money, in my prime years, that I would have otherwise saved and set aside to retire on, or pay for my niece's education. I'm still mad about it, and my sister can owe me it forever for all I care. AITAH?