A 9-year-old girl who spotted a newborn baby wrapped in a towel in her backyard is a "guardian angel," a sheriff said, after the girl's mother alerted Indiana police who helped get the baby to a hospital.

The newborn is expected to survive. Police said her umbilical cord and placenta were still attached, and she may have been in the backyard for as long as a day.

Elysia Laub, the girl who found the baby on Monday, told WBBM she had help finding the baby: from "God." She added, "It just freaked me out, I didn’t know what it was."

Her mother carried the baby inside and called police to their home in Lowell, the Lake County Sheriff's Department reported.

The baby had a sunburn but was doing OK otherwise, officials said. They named her "Miracle Baby Jane Doe."

Police searched the area with dogs and a helicopter but didn't find the mother. Police collected evidence from the scene.

Laub's family reportedly keeps pigs in a pen, so at first the girl said she thought she was looking at a piglet.

"The baby was found in a very rural area, and to think if the 9-year-old wouldn't have gone outside, this could've had a very different outcome," Sheriff John Buncich told reporters. "The department has taken a really personal approach to this case."

He said a foster home would take the baby after doctors released her.

Lowell is about 50 miles southeast of downtown Chicago.

The Associated Press contributed to this report.