Adding on to her appearance, it would be nice if she were older since you have her history panned out. Maybe just changing her appearance or nixing out the fact that she looks younger. Just stick with an inconspicuous appearance. 

I don't see any harm having her be a foster mother if its for the sake of the plot and not just an added feature to Qingge's history. Also, regarding her sudden jump to the Vongola from the triad... Is there a specific reason why Lin-lin told her to change? Was Qingge in danger of staying with the Triad? From what I've read, she seemed to be a good fit for that organization.

And should I wait for Hasayo or should i post?