The correct one is: Who is she married to?

Who is she married to?

this sentence is a trick. teacher Peachey is right . mairried can not only be used as verb ,but also be used as adjective. if you think it's verb, you may say : marry or married sb ,if you think it's adjective .don't ommit the preposition "to".that's all.

"Who's she married to?" - who is she married to? "Who's she married?" - who has she married? Pretty obvious. ^^