"1922! Good year- er, just be careful with the stock market in 1929. I'd definitely pull out my investments before then if I were you," She nodded and smiled. "Yes! An alien- well, alien to you. Time Lord. We look human, but different on the inside." She could go into details about that later, instead choosing to gloss over it a bit.
"What did the future you saw look like, exactly??" She was intrigued, what could an alternative future look like in another dimension??"
"So you were in South America?? Where? Not lookin' into the Aztecs, I hope- wait, 1922. Probably didn't have problems with that lot, then. Sweet people, just interestin' ceremonial habits."