AITA for telling my friend not to date a girl

I know the title sounds shitty but hear me out before you judge me.

**Background information**

My friend (we will call him Derek) and I have been friends since 2020. I started dating his cousin (we will call Ryan) in 2021 and are engaged. Ryan and Derek lived together before I moved in. Ryan and I are 19. Derek is 22

Derek and I always come to each other for advice. Whether it would be about finances or just our personal life. Recently Derek has been coming to me for advice about this girl he has been talking (we will call Jada) for almost a year now. When he first started about her, I thought she would be good for him. He talked about how She has 2 kids. A few weeks later, Derek was upset for a long period because she would ghost him and leave him on read. He would go through the same cycle with Jade for a year. For a week they would be talking than the next he would get ghosted for a week sometimes a month.

Around a month ago, a family member of Jada was in town (jadas aunt) and notice Derek out in public with my fiance and I. A few days after, she contacted me via Facebook and said

" hey this is jadas aunt. I want to warn you that whatever Jada has told you or Derek is not true. please don't believe anything Jade says or does. She puts on this act of how she loves her kids and takes care of them. But in reality I have temporary custody over her two kids due to her mental health. The reason why she don't have her kids is because she left them alone at home while she was at a bar" Jadas aunt also mentioned "She got pregnant when she was 15 on purpose and got pregnant again at 17 on purpose. She would date guys and try to lie and say shes pregnant with there kid"

When Jade ghosted him again I told him "I don't think she's good for you. She keeps leaving you on read and doesn't talk to you for weeks" . He took my advice but just a few days ago, Jada called while Derek, Ryan and I were driving home. Ryan made joke about their conversation and Jada started being flirty. Ryan insisted for her to stop because Derek was right infornt us. She hung up and Derek didn't even care that this girl he liked was flirting at Ryan. A few days after, she FaceTime Derek while I was in the room helping Derek out with paperwork. Jadas kids started crying in the background and for the 15 minutes her kids were crying she was still talking to Derek. When one of her kids walked up to her crying she said " ew go away your diaper stink" 15 minutes after she didn't acknowledge to her kids still. So I walked out the room pissed. An hour later Derek asked why did I leave the room and I said because your hoe doesn't know how to put her kids first 😑 is this really the person you want to be with .if she can't take care of her kids then she not gonna take care of you. He got mad and stormed off