I think the only thing that truly hits me is the vagrant part.
First, the mom dies and the sheltered Yamataian wants to wander. That's OK. But what did the mother leave her? Anything? Clothes on her back? Cash? Etc.
Second, where did she wander to? Yamatai's been pretty darn safe for a long time, depending on what cities she wandered to (Eastern Yamatai being a bit more rough-and-tumble than Western Yamatai).
Third, where did she get her street smarts? Most streetwise people I know aren't giving, or bubbly, or trusting. They're survivors, especially if they lived on the streets. Why is she not more like that?
I'm not pointing these out as flaws, per se, but as things that don't add up. Essentially you gave your character a fairly long backstory, in terms of years, but you don't pin down the facts well enough to define how it all went down. That's what I'd look for.