First, "advocate". This is not a lawyer. It is a person who provides practical information and help and emotional support and advice to victims.

"What is a Victim Advocate?
Victim advocates are professionals trained to support victims of crime. Advocates offer victims information, emotional support, and help finding resources and filling out paperwork. Sometimes, advocates go to court with victims. Advocates may also contact organizations, such as criminal justice or social service agencies, to get help or information for victims. Some advocates staff crisis hotlines, run support groups, or provide in-person counseling. Victim advocates may also be called victim service providers, victim/witness coordinators, or victim/witness specialists."
http://www.victimsofcrime.org/help-for-crime-victims/get-hel...

This page contains further details of the training advocates receive and the services they provide.

Note that this site also says: "Some advocates are paid staff, and others are volunteers."

Those who answer calls at the National Domestic Violence Hotline are advocates. There is no charge for their services; they may be paid by the Hotline itself, but those who call do not have to pay:

"We're here to listen.
Reach our trained advocates 24/7 to get the support your deserve. There are no fees [...]"
http://www.thehotline.org/

For victims who want to escape (leave home safely), the Hotline can put them in personal contact with local advocates: not the people who answer the calls at the Hotline but others, who are local (close to where the victim lives) and can provide personal help. The victim does have to pay for their services (this is the USA, and it is a private organisation, not a state social service), but the cost is low.