She returns in Book 4 as a spirit and regains her human form in Book 5.
Yes Elena does come back and she floats because the gravity has not struck her yet and she also acts different she has to kiss to know a person very well.
she comes back as a vampire, then a spirit but changes into a full human but can still sometimes use her white spirit power[good power]
yes, at the very end of dark reunion(book 4) she comes back as a mortal.
Yes, Katherine does come back to Damon in "The Vampire Diaries." She impersonates Elena to create chaos and cause trouble for the main characters.
Vampire Diaries will be returning April 7th in the United States.
21st January
yes on the 24th
October 11 2012
March 15th
october fifth on ITV2
This autumn.... I can't wait!
March 15th