Is there any way I can get custody of my daughter?

If my 11 year old daughter wants to live with me, but her mother has sole legal and physical custody of her, is there any way I can get her? My daughter is unhappy there, spending a lot of time babysitting her step-siblings (3 and 5 years old). She cried all the time when she was visiting her aunt and told her that she just wants to be a kid, and never has the chance to be one. My daughter says she’s afraid to say anything because she’ll get a whipping if it comes out wrong. Her mother has told her that her dad and his whole family want nothing to do with her. (I heard all this from the aunt, who is the mother’s sister.) The mother hasn’t let the father see the child in 3 years, and is just now getting ready to let him see her in 3 weeks. Will the girl get a chance to live with her dad? How can I get custody of her?