@papperless I feel as if Jennette might have it just as bad as LP!Athy. LP!Athy had at least Lily that genuinely cared for her. Although the Alpheus appear to be caring for her, Izekiel literally just shot her down the previous chap, saying that Jennette isn't his priority and he much rather be with Athy, while Mr White is only using Jennette as a tool. Even Jennette feels that disconnect since she only ever calls him 'Mister' instead of Uncle or any other name that might signify familial closeness.
Jennette feels like the outsider in her adoptive family, its kinda understandable that she feels closer to the complete stranger(technically her dad) at least emotionally because he actually pays attention to what she has to say, be it about just little things or her internal dilemmas.
@Flowerthinking Jennette's magic doesn't kill Claude, it just eases the pain but not remove the cause. It was the curse Claude cast on himself to remove his memories that killed him in the end.
As for Athy's magic going crazy, it was Ana that tampered with Jennette's gift that caused the haywire, not Jennette herself. It was way back in season 1.