Because I am also quite the petite gal as well (5ft, 32/25/33 and also chinese hehe) I have some relevant cosplay ideas to share!
Here are some characters that I think could work in short notice:
1. Chihiro- Spirited Away
2. Kiki- Kiki's Delivery Service
3. Sheeta- Laputa: Castle in the Sky
3.Chika Ogiue- Genshiken
Ghibli characters are of course well known and pretty popular and their costume are usually not very elaborate so if you are planning to make it, it shouldn't be that difficult. The characters from Genshiken and Kuragehime are ones on my list that should fit your criteria. Hope it helps!