Her legs are no longer than an adult's pinkie and her feet are about the size of an adult's fingernails. Weighing 11 ounces, Kalea Lyn Allen was delivered three months premature Tuesday by Caesarean section after an ultrasound raised concerns, Dr. John Stanley said.

"She's a survivor," said her mother, 27-year-old Deidra Allen of Sayre. "She's fighting."

The infant has about a 40 percent chance of survival and the first six weeks will be the toughest, doctors said. Many of her internal organs — including her lungs, intestines, kidneys — are underdeveloped.

Kalea will remain hospitalized at Mercy Health Center at least until her original due date of Aug. 12, Dr. Sylvia Lopez said. Deidra Allen is expected to be released in about four days.

Kalea was being kept under a soft plastic tent in the neonatal intensive care unit with a breathing tube smaller than a piece of spaghetti to help inflate her lungs.

"I knew she would be tiny because of her measurements on the ultrasound," her mother told NBC's "Today" show Wednesday. "But I didn't know; I didn't put it into perspective how little she would be."

She's not the tiniest baby. A girl born in September in Chicago is believed to be the smallest baby in the world, weighing 8.6 ounces at birth. She was released from the hospital in February.