AITA for standing up to my daughters father and stepmother

FAIR WARNING THIS IS A LONG STORY. Backstory: I (29F) have a nine year old daughter. Before I got pregnant with her I was seeing two men, not my finest moment, I know.. I didn't find out who her father was until she was almost three. The man who signed her birth certificate when she was born, let's call him Chad, was one of the two men. The other man, let's call him Dave, is a drug addict who lives out of state. Well it turns out Dave is her biological father and he doesn't want anything to do with her, mostly because I told him to stay away until he was no.linger on drugs in hopes of protecting my daughter. Chad and I were highschool sweethearts and we went through a lot together. We loved each other a lot, but just really never fit together which is fine. I was never really good to him and he really was never emotionally intelligent for me. When my daughter was born we really tried to make everything work, but I got sucked back into the emotional bullshit of Dave and admittedly I ended up using drugs and was out of my daughters life for a year and a half. During this time she lived with Chad at my grandmothers house. I finally got sober and I've never touched another drug, I don't even drink anymore. I've been sober for 7 years and no contact with Dave. When I got out of jail and sober Chad tried to take my daughter away from me and move out of state with his girlfriend and so I went to court and got a paternity test done. Turns out Chad is not her father, Dave is. The judge said that Chad has no rights and that he's not her birth father so there's nothing he can do. I never changed the birth certificate though. I never thought of keeping Chad away from my daughter, honestly I just wanted to make him realize that he couldn't take my daughter away from me.. which worked. Chad has been an alright dad to my daughter and everything was going so great. We did every single holiday, every birthday, everything all together as a family. I mean seriously my family (my two kids and my husband) even goes to events with Chad's mom and stepdad. I thought everything was going great, but I'll get back to that. Any way, back to Chad's has had a girlfriend, let's call her Kylie, for I think little over 7 years, like 7 years 2 months. They have a 4 year old son together. So she has been in my daughters life for a long time. However, my daughter in the past two years has been saying that Kylie treats her (my daughter) differently, she's mean, she yells all the time and she's always sick. I've consistently told Chad what my daughter says and nothing gets done about it, or it changes for a while and then she's telling me the same thing again maybe 6months later. Now I have a love/hate relationship with Kylie. I don't hate her exactly, I mostly just don't like that she's been with two of my exes and Chad and every time I change my hair color, she changes hers. I even bought a new couch a few months ago so she got a new couch. I'm not even kidding. But this is where the love hate comes in, because I don't necessarily hate her, I honestly just dont like some parts of her personality. I mostly get along with her for the sake my daughter. Which is what we are supposed to do as co-parents I thought!

Chad came to me two weeks before Christmas while I was picking daughter up, in front of daughter and says hey I think we want to do Christmas by ourselves this year. At first I said oh man that's shitty, but okay and I got in my car and was prepared to take my daughter and go on about our day. But then she starts wailing saying she doesn't want to do Christmas separate and she was just heart broken. So I got out of the car and asked Chad why? First he said because it's not fair that when we come over for Christmas my daughter gets more presents than both her brothers (my other child and their other child). So I said okay I can leave the presents we get her at home or she can open them Christmas Eve, whatever. He said no. Then he says well we got the kids a trip to Disney world and we want it to just be us and we don't want you guys to have to compete with that. And I was like it's not a competition?? My goal is for my daughter to have a good Christmas and it's important for us all to be together. And then I asked was this a you and Kylie decision or a Kylie decision? And he said a little bit of both and I said I don't think so and he starts going off on me and Kylie comes out of the house and calls me a b*tch and it was a shit show. So we have a 30 minute ride back to our house and my daughter is hysterical. She says she hates Kylie, she only wants to go to Chads every other weekend and that she doesn't feel comfortable going over there with just Kylie anymore. She just wants to spend time with Chad. Mind you, Kylie never lets them go out together alone. If daughter wants to go see a movie, get ice cream, go shopping, literally anything with Chad, Kylie invites the whole family. So a couple hours later daughter calls Chad and tells her the same things she said to my husband and I. Then she goes it's either Kylie or me to her dad. That's where the call ended. I let her calm down for a few days and then I asked her if she still felt the same way. She said yes. Two days later, same feelings. So what am I supposed to do? I support her. Chad and I sat down and I drew up a parenting plan to take to court and get everything in place for daughter to go over there only every other weekend. He refused and we got into an argument where he called me a bad mom for letting her decide this and said and I quote, "because your mom didn't love you, you love her 10 times more" and once again I quote, "daughters emotions don't matter and she shouldn't be able to make life decisions at 9 years old". And then he told me I was not family just because I birthed her. At this point I was over it. I told him until we could all get into family therapy, sign the parenting plan, and until daughter changes her mind, which I hope happens!, she's not coming over there anymore. But at this point he wants to go to court and make sure his "rights aren't messed with" and I want to take his name off the birth certificate and be done with the whole mess. I honestly don't know what's best for my daughter, what to do, or how to make an unbiased decision on anything because of how many emotions are involved. I guess I want to be the asshole and just take his name off so that no one can take away my daughter from me. I am her only biological parent in this whole situation. It all doesn't seem fair. Please help. Also, we have a meeting setup for sunday where all four of us, Chad, Kylie, my husband and I, will sit down and try to talk things out peacefully, but I'm so nervous and I would appreciate any advice.