The obvious name for you seems to be Julia, as that is very similar to your own name. It also has equivalents in all Western languages, so people from other countries would have no problem saying it.
In English-speaking countries, people don't attach importance to the meaning of names in the way that you do in Chinese culture. However, Julia is a pretty and feminine-sounding name which certainly strikes me as a suitable for a quiet girl.
I hope you like my suggestion.