So basically other people are singing her songs? Also why does Mariah Carey not like her? Is it because of this?
She provides vocals and then other people sing on top of her and provide the parts she can't hit. Or they keep the demo track and she just puts her voice over it. Ever wondered why she rarely sings live? She's gotten a lot better with singing and I think she worked on it a lot, but in the 2000s and 2010s as far as I remember, most of her songs had ghost singers.
J.Lo worked with Mariah's abusive ex husband after Mariah managed to get away from him. He kept her locked up and groomed her from an early age and stole her catalogue/songs she's written and/or worked on after she escaped their home and Jennifer knew that but still accepted her songs so I think M has a lot of reason to dislike her.
I meant like legally
I don't really know. I assume they received some compensation for working for her?