The women voluntarily followed the 416 children, taken two weeks ago from the ranch.
State authorities say the children may be victims of physical and sexual abuse.
A custody hearing for the children is set for thursday, and each one of them must have representation.
A member of the Texas State Bar Association's Board of Directors says he's trying to ''round up,'' as many as 350 lawyers to work on the case.
"When these lawyers get appointed, they're going to go out and interview the children, they'll probably interview the parents, they'll look at all of the evidence and ultimately the ad litems will make a recommendation to a court, or they will advocate for their client," Tom Vick, with the State Bar of Texas, said.
The children were seized after a 16-year-old girl reportedly called a family violence shelter and said her 50-year-old husband beat and raped her.