It has already been shown on television that Mariah does not manage her own social media. Demi has a big mouth and got skull dragged for it. Deal with it hun!
So she doesn't watch the Grammys, the AMAs, the VMAs, the BBMAs, the X Factor, American Idol guest performances (where she once judged)?
She's close friends with Beyoncé and she didn't know Drunk In Love when it was #2 on Billboard and super popular, Mariah doesn't seem the type to follow this generation's pop music, especially the subpar C-lists like Demi Lovato.
she says "I Don't Know Her" for people Mariah didn't met personally or isn't in contact that much. She already explained that about J.Lo and she even said that about Demi