Hello! I have just one, also an AP, and that's this big ol' brute. Name's Erik, not a super friendly guy, but a nice guy. He's not the sort to hold grudges, but isn't particularly outgoing at all. HE's several years her senior, so he definitely could be her mentor type, or even the bro type. Older, helped her out against some of those frenemies of hers, showed her the ropes in fighting. Since she's going to apparently be friends with Ember, that actually plays well as they're kind of buds too.
He knows fighting, not much else, but he knows that, so could definitely have taught her there.