is taylor swift a christian?

Based on the fact that she released Christmas songs yes she is a Christian. She may have other songs that have direct reference to God and Jesus, but that I can not state, since I'm into the more traditional style of country music, and not the modern pop style country she performed.

Yes

Yes, She is!
http://www.lyricsmode.com/lyrics/t/taylor_swift/christmas_must_be_something_more.html