Daugther from previous marriage does not like her step father

I am a divorced mother, separated for three years due to Domestic Violence with my previous spouse. I am engaged to be married and have a seven year old daughter. Although her biological father has not been in our lives for three years because his whereabouts are unknown, she does not want me to be with anyone. She says she doesn't like my fiance, yet she tells him she loves him and calls him Daddy. Why would she feel this way? I don't know what to do.

She might be jealous and might want her mother for herself. She likes your fiance but she wants him for herself and does not want to be locked out from his and your community. Wait until your daughter accepts that he moves in with you. Take it slowly and gradually.