Um, you're not thinking like a Time Traveler. For instance, I don't really think of 2010 as the Doctor's "home time" - and I don't think that would ever be specified. So obviously he can *meet* her for the first time - or specifically she can meet him for the first time - whenever he runs across her. He doesn't have to live until the 51st century in a linear way, because he's a Time Traveler!