If you're her legal guardian and she's not an adult, she legally can't move out. If she did try to move out -- like if she started staying at her boyfriend's house and won't come home -- call the police. She's technically a runaway at that point.
Also, if her boyfriend is abusive, consider looking for counseling for her. If she won't go see a counselor, see if she'll at least contact us at the Boys Town National Hotline: 1-800-448-3000. We'd be happy to talk to her or you if you guys needed help.
Boys Town National Hotline
If you have physical custody then you can.Depending on the state the child can not do it unless they are emancipated. But when she turns 18 you can't stop her. The best bet would be to research it as well as contact local authority. They would be able to tell you more.
smh.. you need to handle that fast cause i been there and done that with a man beatin on me!!!!!! just call the cops fast cause when she turn 18 you cant really do nuffin or the cops cant do anything cause by that time she grown.....and i dont understand why she want too move in with him if he keep doin stuff to her....smfh i dont understand..just try to talk to her more...c if it workk...