I discussed some of this with my siblings the other day. Why would a 3000 year old (or so...don't have my books here) woman be interested in a sixty year old man anyway? Couldn't she find someone a little sooner, maybe?
Not to mention I'm not sure Elrond would be a barrel of laughs to have as a father-in-law. Yikes!
I've wondered that. And besides, don't you figure once she becomes mortal those 3,000 years are gonna start catching up with her?
And of course, father (The ring is not my problem) Elrond will say to Aragorn, "She's your problem now..."