这句话最难译的是小家碧玉”. 据描写上海这种女孩的英语是: 与上海一起成长的“小家碧玉”. The so-called “pretty girls of humble birth” in Shanghai traditionally mean the daughters of ordinary families living along old tridition.
所以楼主这句译成:My girlfriend is a pretty girls of humble birth, fits my taste very well.