Sometthing that no one noticed, but is an even BIGGER reveal about Geillis's status as a time traveller, was when she used the word 'fucking" as an adjective, as in "fucking barbecue." If you recall in a previous episode Jamie had to ask Claire what that word meant. It wasn't a common word in 18th century Scotland.…

It's all revealed in the books. :) The one thing that's great about the series is that even though it has added so much texture and new storylines, it's sticking very closely to the events in the book. If they do one book per season, you'll find out all about Geillis in Season 3