ST. LOUIS, Mo. – A family’s desperate search continues for a missing St. Louis mother. This comes after the father of her four children was arrested in Wisconsin on Friday after the couple vanished last week.

The family of Marquisha Williams spent Sunday searching for her remains in central Illinois, as St. Louis County police informed FOX 2 they had suspended their search efforts there. The frantic search for the couple has now turned into a search for just Williams.

Williams, 29, was last seen dropping off her kids in north St. Louis County around 6 o’clock Wednesday morning before her 7 a.m. shift at work. But she never made it to work. Williams was with the father of her four children, Trenton Ivy, at the time. The couple was reported missing after disappearing a short time later.

The couple’s 11-year-old son said he heard his parents arguing in the car that morning. Williams’ mother, Norvette Chavis, told FOX 2 that Ivy’s arrest two states away confirmed her worst fears.

“My thoughts were that he had done something to my baby, that she was deceased, that she was gone,” Chavis said.

Ivy has not been charged in Williams disappearance.

On Sunday, Chavis led a caravan of roughly 40 family members and friends, spanning 10 vehicles, in a desperate search for her daughter.

The group drove north on Interstate 55 toward Chicago, looking for any signs of the 29-year-old near the east side of the road. They told FOX 2 police informed them Williams may have been left near the interstate, possibly covered with a dark-colored blanket or cloth.

Chavis said the couple has a history of domestic violence. She hopes people will see this story and take red flags seriously.

“Pay attention, pay attention, pay attention. When someone’s trying to leave, let them leave,” Chavis said. “I never thought that he would take her.”

As this St. Louis family braces for the worst news of their lives just a day before Christmas, a mother is focused on just one thing.

“I just want her back. I just want her back. I can’t live not knowing where my child is,” Chavis said. “I just want her back.”

At present, Ivy faces three charges: use of a dangerous weapon, resisting an officer, and fleeing from an officer in a vehicle. He is being held on a $10,000 bond in Racine County, Wisconsin. He has not been charged with anything related to Williams’ disappearance.