Police continued to search Thursday for a missing 10-month-old Missouri girl, as her sobbing mother told reporters, “I can’t be without her.”

Asked why someone would want to kidnap Lisa Irwin, the girl’s mother, Deborah Bradley, said, “The only thing I can think of is maybe somebody wanted a baby.”

“She’s everything,” she said of Lisa. “She’s our little girl. She’s completed our family and she means everything to my boys. We need her home. I can’t be without her.”

The girl’s father, Jeremy Irwin, urged anyone with information to call police. “Anything, even the smallest information, could help lead to her return,” he said.

Lisa Irwin was last seen around 10:30 p.m. Monday, asleep in her crib, Kansas City, Missouri, police said. Police were called to the home at about 4 a.m. Tuesday.

“It appears the suspect entered/exited through a bedroom window,” authorities said in a statement. “Evidence at the scene leads police to believe the child has been abducted.”

Jeremy Irwin told reporters he found Lisa missing when he returned home from work. “The front door was unlocked,” he said Thursday. “Most of the lights were on in the house, and the window in front was open — all very unusual.”

Police have said the parents are not considered suspects in Lisa’s disappearance. Police Capt. Steve Young on Wednesday told reporters the family has been cooperative from the beginning of the investigation, but “everything is still on the table. We haven’t ruled anything out.”

He said Wednesday investigators “really haven’t developed any good, hard information that we can go forward with.” Nearly 50 tips have been received through a tip hotline, he said, but not all of them have been pursued, as some of them have been vague — a person calling to report a child seat seen in a car, for instance.

“I know everybody’s hearts are in the right place, but that’s not anything we can do anything with,” Young said.

Police have conducted more than 300 “knock-and-talks” and searches of residences in the area, and more than 300 officers were searching for Lisa. There have been three searches of a wooded area near the family’s home, he said.

“I promise you, if there’s anything we think we can be doing, we’ve probably done it two or three times already,” Young said.

An Amber Alert was issued for Lisa early Tuesday but has been canceled. “Although the investigation and search for Lisa Irwin continue, an active Amber Alert is no longer necessary in this case,” police said. However, Lisa is still considered missing and endangered, according to authorities.

Lisa is described as 30 inches tall with blue eyes and blond hair, police said. She weighs between 26 and 30 pounds. She was last seen wearing purple shorts and a purple shirt with white kittens on it. She has two bottom teeth, a small bug bite under her left ear and a “beauty mark” on her right outer thigh. She currently has a cold with a cough, police said.