Viuda and Soltera

Can the terms "viuda" (widow) and "soltera" (spinster, or single woman) be used interchanged? That is, could "soltera" describe a women who is actually a widow?

I have a 1739 death record from Aguascalientes for Josepha Rodrigues where "soltera" is used. Her parents are named, but there is no other information. I also have what may be her husband's (Salvador Ponse) death record from 1738, where it states that he is married to Josepha Rodrigues.

George Fulton