AITAH for getting a modification to my child support payments because I found out she was using some of the money not for our child?

Before anyone jumps down my throat I did this all with my attorney and it was granted by a judge. So I am not sneaking legal advice.

Situation is as follows, around five months ago I made a request to modify my child support payments since I found out she was using the extra money on herself. I spoke with my attorney and he stated it was within my right to request a modification. We had the hearing a month later, everything was looked over and I was granted the modification to pay less. As per the judge child support is meant for the child not for my ex's lifestyle.

The topic came up during our family get together my mom is still on good speaking terms with my ex. My mom was unaware I got the amount changed. She was upset with me. She claims because of me she has to give my ex extra every month. I tried to tell my mom she is playing her and getting a modification is not a simple thing it does not happen without approval.

My mom thinks I lied, but I tried to explain all I did was request the modification provided my proof and what happens or requests are made of my ex by the judge is between them. I told my mom the judge must have agreed or they would not have granted a modification.

She claims even if she was using the extra for herself that is okay. I Am confused by my mom and now I am wondering am I an asshole even though I was within my rights to request a modification?