AITA for inviting my child's ex spouse to Christmas

I (47f) have only one child (26?). I am not like other boy moms. I sadly could not have another child and I've always wanted a daughter so I saw him getting married as gaining a daughter. Not losing a son. He married his highschool sweetheart and I had a huge soft spot for her because I saw a lot of myself in her. She had been through similar things that I had been through. She moved in with us when she was 16 because her own father was raping her. I was sexually abused for years by my step dad. I completely understood her. She also suffered from borderline personality disorder. Another thing I suffered from. I wanted to be the mother to protect her that she never had. The problem was she never tried to get help. My son and her married when they were 19 and 20 and got divorced before My son's 22nd birthday. She would get upset which in return caused her to get violent. My son left their honeymoon early because she got mad and got violent. I had been trying to help him help her but she wasn't getting the help she needed. I had a soft spot for her because I saw so much of myself in her and had no one given up on me I would have possibly turned out differently. They had a fight where my son tried to leave and she got upset and purposely slammed his hand in the door and refused to open it. That was a turning point for her. He had to go to urgent care over his hand and she decided to get help. She didn't want to be like this anymore. I was proud of her but my son decided he wasn't dealing with this anymore and even though she was going to get help he served her divorce papers. I tried to talk to him to try marriage counseling first but he left. Which was his choice. I stayed in contact with her. Him leaving her caused her to spiral and only get worse. She got arrested for assaulting a date she went on. And I was sad for her because she was finally wanting to get better.

This Christmas I found out she has no one to spend Christmas with and I felt bad so invited her. My son wasn't happy and neither was his girlfriend. He started dating his girlfriend a few years ago. She's an Asian girl and he let her at a strip club... She was stripping. I was not the happiest that he fell for a stripper but she's a lot like him. She's a huge gamer. He got her pregnant and they had a game style baby shower and had a daughter that is almost a year. She's also no longer a stripper. She was just using that to pay for her trade school and ia now a dental assistant. He's not happy that I invited his ex wife and claimed I've made no effort to bond with his girlfriend. I'm nice enough to hear but I have a bond with his ex. Plus she's all alone for Christmas. My son said if she's there, him and his family won't be. Was this a mistake? Am I being disrespectful? Am I an asshole?