Thanks for asking me about your Sterling China cup & saucer set, I would be happy to help.
It dates to the 1930s - 1950s when these European style rococo revival cup & saucer sets were much in vogue, copying the Dresden style of a pierced (or reticulated) saucer and a fluted, pedestal cup. The decoration consists of brocades of traditional rococo latticework in gold on cobalt blue (a motif much prized by Russian porcelain collectors, incidentally) and interspersed with scattered flowers in gold.
Sterling China was a US importer of fancy china ware that probably evolved out of an earlier company called Empress China that operated in the 1920s and 1930s, though very few records exist about the structure and history of either.
It has nothing to do with the US based manufacturer, "Sterling China" of Sebring, Ohio, it's just unfortunate and confusing that they both have the same name.
Sterling China (Japan) seems to have quite a steady following of collectors on line, I'm glad to report. Looking at comparables, if you were to sell your cup and saucer at auction or on line (eBay etc) it would fetch in the range of $30 - $45.
It therefore has a full retail/replacement/insurance value of $90.
I do hope this helps!
You are most welcome!