Holy shit, that's TIFA! Finally after so long she plays a role again. Its been so long i didn't expect it at all.
Being raised by a former editor with passion for books explain why Tifa's adamant on theo's education. (Remember that scene when she persuade theo the importance of learning? That's my favorite scene in this series).
hmm so why did tifa run away with theo from that orphanage? sae's father seems great
It probably not him, but everyone else around. The society, maybe even other relatives, may well looked askance at Lumino raising a amity child and pressuring him about it. Thus Tifa run away, partly to protect theo, but also so to not burden Lumino and the rest of the orphanage. That's my guess.