Though she plays a more minor role in Advent Children than in Final Fantasy VII, Tifa did battle against Loz and later, against Bahamut SIN. She has shorter hair than her original character design mainly because animating long hair was proven to be quite difficult.
She looks like an older, more mature version of Rinoa to be honest. But I think a few people will get mad at me for saying that. Beautiful cosplay though! And the characters for the cosplayer’s name means “little fish”, Xiao Yu. Great cosplaying!
EDIT: My bad. I don't know my pin yin. Corrected it now, thank you, xii!