(NewsNation) — As police call off a search for missing Minnesota mom Madeline Kingsbury, her family and friends still hope she will be found.

Kingsbury disappeared on March 31, according to Winona Police. The last person to see her was the father of her two children while she was dropping them off at daycare. He says he borrowed her van and hasn’t seen her since.

The last known communication from Kingsbury was a funny text to her sister. She never showed up to pick her children up from daycare and her phone, ID, and wallet were left at home. Police have called her disappearance “suspicious and involuntary” and thousands of people turned out to search for her.

While police have called off the ground search in Winona, a southern Minnesota city located along the Wisconsin border, the investigation into Kingsbury’s disappearance is ongoing. Kingsbury’s mother, Krista Naber, said the family is hoping someone will come forward with information.

She told NewsNation’s Ashleigh Banfield that police have expanded their search into Houston County in Minnesota’s far southeast corner.

Naber described her daughter as a hard-working mom.

“She took care of her two babies. She had started graduate school in January, things were really finally looking up for her,” Naber said.

Kingsbury drove a dark blue minivan, which was last seen driving down a county road. Naber couldn’t say if police knew who was driving the vehicle at the time.

“We just remain very hopeful each day that we get closer to finding the missing answers and to bring our daughter home,” Naber said.

There is a $50,000 reward for Kingsbury’s return. According to the Minnesota BCA, Kingsbury is 5 feet, 4 inches tall, weighs 135 pounds and has brown hair and hazel eyes.

If you have any information, you are asked to call the Winona Police Department at 507-457-6302 with any information. Tips can also be submitted anonymously to Winona Area Crime Stoppers at www.crimestoppersmn.org or at 800-222-8477.