I knew she was an elf from the first time she showed up! Anyway, so how did her blood help seal the god of fire in II?

Because "she" is half-orc I guess

Perhaps; it's not at all clear though as she claims to be an elf, branded as a disgrace and exiled.

EDIT: OK, in the second playthrough, it was clear. Early on there's a comment that makes it so that I either didn't get or forgot. She is an Elforc. :)

I also missed a lot in the first playthrough. So this time, after the end, I left Darpha and went to find my fiance. I thought maybe there'd be something said, perhaps, "I got elected mayor and I don't think it will work with you out adventuring and all" or something like that. Perhaps and Easter egg on the bulletin board but, nada. Oh well, it's a fun game and I really wish that they'd been successful enough to finish TW3. I'll probably play it one more time as a mage but, by the gods, mages are so weak in this series.