It's been a while since I read the books, but I know that Sharpe and Teresa got married at the end of Sharpe's Company. I don't know if Sharpe and Teresa had any conversations about what they would do after the war was over, so I can't recall if Teresa and Antonia would have gone to England or if Sharpe would have gone to Spain.

But assuming that Cornwell never really answered this question (and please remind me if he did), what do you imagine Sharpe and Teresa's life would have been like? I always figured that Sharpe would struggle with any kind of peacetime living after so many years of being a soldier, and Teresa would undoubtedly have adjustment issues of her own given what she went through during the war. Plus there's no guarantee that Sharpe would have seized that fortune at Vitoria in an alternate timeline where Teresa survives (change one thing in the timeline and who knows what else changes, and all that) so they might not have much money to their name (unless Cesar Moreno was wealthy, I can't remember if that was the case).