Yes there will be legal issues. Lots of legal issues. I would hire a lawyer to change custody (telling the father he does NOT have to pay child support).
Legally, a child is under the control of his/her parents until eighteen, until there is automatic emancipation and the child is considered an adult. A child can technically leave the house, but the parents can have the child brought back by police, unless there is (sincere )accusations of neglect and/or sexual/verbal/ other abuse, in which case the child would likely be placed in foster care while the allegation is investigated. Caution - making false allegations of abuse is a crime in itself.
Assuming no such abuse exists, if the child wishes to emancipate before turning eighteen to end the control of a parent, In Texas, the child can do so through Court by asking for emancipation. In Texas, emancipation is called Removal of Disabilities of a Minor. The governing law is Texas Family Code's Chapter 31.
In short, the law requires that the child requesting Removal of Disabilities of a Minor by the court show: 1) that the minor is at least 16 years old, living separate from the parents, and, 2) the minor is self-supporting and managing his/her own affairs. The parents will have to be served (notified) of the petition and will have the right to challenge it such a petition.
It is possible to do this yourself, but highly advisable to use an attorney. A typical attorney fee for such venture would be anywere from $1000 to $2500, or even higher, depending on the case.
At the very least, it is advisable to pay a legal consulting fee and speak with an attorney about steps to take, if you should wish to do this yourself. The consulting fees vary from attorney to attorney.
The answer to your question is yes. Would love to have a consultation to learn more about the situation because it may sound like you could involve some other agencies to help you. Please, contact us for more information.