Hello Lily! Lis here and I know we've spoken at length. I'm so excited to see you here. Also, librarians are cool so you're already aces in my book.
Daisy adores Neville, though she hides a lot of it behind sarcasm and being a bit of a bitch at times. She DOES treat him just like Neville (and it is pretty much why she has a little bit of hero worship, because he is SUCH a good guy) and has a big honking crush on him. I'm open to anything between the two of them, even if perpetually treats her like a little sister.
Caradoc might not know Daisy very well, but that entirely depends on how well he knows her parents/if she's friends with his niece/nephew. Otherwise, she's willing to talk to practically anyone and everyone. And by talk I mean annoy. Enjoy :D