Dennis and Bridget Lenihan, of Oak Lawn, with their children Gabby, 5, Clare, 11 months, and Jimmy, 7, Wednesday, December 19, 2012. | Brett Roseman~Sun-Times Media

Nurse Dorothy Gut examines Violet Sheppard in the neonatal unit at Advocate Christ Hospital in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Nurse Dorothy Gut gently hands the Sheppard family twins to the proud parents, daughter Violet to mother Elisabeth and son Cameron to his father Dennis, in the neonatal unit at Advocate Christ Hospital in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Nurse Dorothy Gut measures Violet Sheppard in the neonatal unit at Advocate Christ Hospital in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Elisabeth and Dennis Sheppard gently wake their premie twins Violet and Cameron for a diaper change in the neonatal unit at Advocate Christ Hospital in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Elisabeth and Dennis Sheppard gently wake their premie twins Violet and Cameron for a diaper change in the neonatal unit at Advocate Christ Hospital in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Elisabeth Sheppard gently maneuvers her daughter Violet out of her pajamas for a diaper change in the neonatal unit at Advocate Christ Hospital in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Dennis Sheppard holds the hand of his daughter Violet in the neonatal unit at Advocate Christ Hospital in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Violet Sheppard stretches in the neonatal unit at Advocate Christ Medical Center in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Nurse Dorothy Gut gently hands Dennis Sheppard his son Cameron in the neonatal unit at Advocate Christ Hospital in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Dr. Benjamin Ticho consults with parents Elisabeth and Dennis Sheppard before he checks the eye development of their premie twins Violet and Cameron in the neonatal unit at Advocate Christ Hospital in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Dennis and Bridget Lenihan, of Oak Lawn, with their children Gabby, 5, Clare, 11 months, and Jimmy, 7, Wednesday, December 19, 2012. | Brett Roseman~Sun-Times Media

Nurse Dorothy Gut gently hands the Sheppard family twins to the proud parents, daughter Violet to mother Elisabeth and son Cameron to his father Dennis, in the neonatal unit at Advocate Christ Hospital in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Elisabeth and Dennis Sheppard prepare to feed their twins, daughter Violet (left) and son Cameron (right), in the neonatal unit at Advocate Christ Hospital in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Dr. Benjamin Ticho checks the eye development on premie twin Violet Sheppard in the neonatal unit at Advocate Christ Hospital in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Clare Lenihan, 11 months, plays at her family's Oak Lawn home Wednesday, December 19, 2012. | Brett Roseman~Sun-Times Media

Dr. Benjamin Ticho checks the eye development on premie twin Violet Sheppard in the neonatal unit at Advocate Christ Hospital in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Clare Lenihan, 11 months, plays at her family's Oak Lawn home as her mother, Bridget, watches her Wednesday, December 19, 2012. | Brett Roseman~Sun-Times Media

Dr. Benjamin Ticho checks the eye development on premie twin Violet Sheppard in the neonatal unit at Advocate Christ Hospital in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Pictured of Dennis and Bridget Lenihan's children; from left, Gabby, 5, Clare, 11 months, and Jimmy, 7, Wednesday, December 19, 2012. | Brett Roseman~Sun-Times Media

Nurse Debra Skopec calms premie twin Cameron Sheppard with the touch of her hands after an eye development exam in the neonatal unit at Advocate Christ Hospital in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Elisabeth and Dennis Sheppard look on as their premie twins Cameron and Violet relax after an eye exam in the neonatal unit at Advocate Christ Hospital in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Dr. Mario Sanchez finds what was the smallest premie baby delivered at Advocate Christ Hospital on a data base in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media

Elisabeth and Dennis Sheppard look on as their premie twins Cameron and Violet relax after an eye exam in the neonatal unit at Advocate Christ Hospital in Oak Lawn, Illinois, Thursday, December 13, 2012. | Joseph P. Meier~Sun Times Media