Can a minor (17.5) leave home without the consent of their parents?

I am a lawyer in CT and practice in this area of the law.  If the legal age in WA to consent to contract is 16 years old - which i believe it is - then the minor may move out of the house and enter into her own lease agreement and live on her own.  If the parents are abusing the girl the girl should call the police and let the state know so that the parent can get the help they need.  The girl may want to go a foster home as opposed to being out on her own as she will not be able to afford a decent living environment.  if the girl can stay with a friend or relative, that would be preferred.

In Washington state the age of majority (that is adulthood) is 18.  Until then a minor must remain under the legal control of their parents unless they are "emancipated".  Emancipation is a legal process whereby a minor is deemed to be an adult.  A court would have to rule on this.  In order to have it do so, it would have to be demonstarated that the minor was mentally competent, financially self-sufficient, had a safe place to stay, etc. However, in this case, by the time this was done the minor would have probably reached majority age. 

There is probably an better avenue to take.  Due to the alleged abuse, the minor could report this to the state's social services department.  If proven true, and in the meantime, the minor can be removed from the home.  Considering the minor's age (17.5), it may be possible to be placed with a friend or relative until they turn 18.

Right now they should consult with an attorney in the area as to their legal rights in this matter.