DENVER (AP) _ A newborn baby girl was found safe and reunited with her mother Thursday, two days after she was stolen from a hospital room by a woman posing as a hospital technician.

''Thank God, my baby's back,'' Sherry Frohm, 25, of Wheat Ridge said as she held her baby, Julia Renee. Hours earlier Frohm had made a televised appeal for the return of the infant.

The baby, who was stolen Tuesday, was found Thursday afternoon at a Denver home by officers investigating a disturbance, said police Sgt. Dan Yount.

They arrested a 21-year-old woman living at the house as a suspect in the kidnapping.

Both the child and the suspect, Michelle Reef, who appeared ill, were taken to Denver General Hospital for examination, police said.

Pediatricians pronounced the child in excellent condition, and she was reunited a short time later with Frohm at St. Anthony Central Hospital.

Police expected to question the suspect at police headquarters later Thursday, Yount said.

Police had earlier theorized that the baby was taken by a woman who lost a child recently, through death, abortion or miscarriage. Frohm said she agreed that was a likely motive.

''If she has lost her baby, she has to know what this is like for me,'' Frohm told reporters at a news conference Thursday before the baby was found. ''It's just that I can't understand her actions. I can't comprehend her reasons for doing this.''

Julia Renee was born Sunday.

On Tuesday a woman dressed in a white laboratory coat with a name tag on it came into Frohm's hospital room and inquired after the health of the mother and baby, Frohm said Thursday.

The woman said she wanted to weigh the baby and took her away, Frohm said.

She said it seemed the only reason Julia Renee was abducted was ''just because she's a beautiful, normal, healthy baby.''

The child's father, Brian Braun, 27, has shared a house with Frohm and her 4-year-old son by another man. Frohm said Wednesday that she had not spoken with Braun since the baby's birth.

The FBI entered the case Wednesday, alerting authorities in Utah, New Mexico and Wyoming to watch for the missing infant. Her photo had been widely publicized.