I know Quent isn't related to her, but he is like a father to her so that's good enough for me. She was Quent's son's dog. Before she realized she was half wolf she hunted wolves down and killed them along with Quent. But when she met Cheza she realized she too, was at least half wolf, and could turn into human form like the others. Quent wanted nothing to do with her. She and Hige become real close. I guess you could couple them together if you wish.

[Spoiler]

How does it end for Blue?
She gets killed by Darcia.

Does she die alone?
No she's not alone, Hige is with her.