jurisdiction for defamation lawsuit

[Joan_Findlay]

I live in Atlanta, GA and want to file a libel lawsuit against my sister who lives in North Carolina. The libel involves lies in emails sent to a guardian ad-litem for my father, who lives in Alabama (both the guardian ad-litem and my father live in Alabama). We have proof that the statements in the emails were false.
Where do I file the lawsuit: in NC, Alabama, or Georgia?
Thanks very much.