By Syma Chowdhry

CHESWOLD, DEL. (CBS) — Hundreds of volunteers joined the search Sunday for 35-year-old Keisha Hamilton, the mother of four who disappeared more than two weeks ago from her home in Symrna, Delaware.

“We are willing to do anything we can to find her,” said Janell Foster, Keisha’s sister. “Our family is committed to finding Keisha and we are not going to stop until we find her.”

Family members, with more than 300 volunteers, combed through woods and fields in Smyrna, searching for Keisha. She was reported missing on January 10, along with two of her four children.

“We are here because Keisha is caring and loving,” Foster said, “and she has four children who are desperately trying to find their mother. So we appreciate the community support.”

Soon after the disappearance, Keisha’s husband Cortez Hamilton was found in Indiana with their two children, who were both safe. But there has been no sign of Keisha. Family members believe her husband is responsible for her disappearance.

“I believe the same thing — that he has done something horrific to my sister,” said Foster. “Because he is a horrible person.”

Hamilton was charged with endangering the welfare of his children and assault. He was extradited back to Delaware on Friday. He remains in jail, but has not been charged with any crime related to Keisha’s disappearance.

More than 20 state police troopers helped lead the search Sunday morning.

“They don’t want to leave, as well as law enforcement, don’t want leave any stone unturned,” said Sergeant Richard Bratz with Delaware State Police. “We are doing everything we can with the resources we have to help search for her.”

Anyone with information on the whereabouts of Keisha Hamilton is asked to contact 911 or call Detective David Weaver at 302-731-2728.