Emmanuella Osei, 23, gave birth in a restroom at her Pennsylvania job in January
She had denied her pregnancy to her friends, family and co-workers
Osei gave birth January 16 and her son was found inside toilet at assisted living home where she worked
She was surrounded by blood and an umbilical cord when cops arrived at scene
Police performed CPR on the newborn who was cold and unresponsive
They believe the baby had been submerged for 10 to 15 minutes in toilet water
Baby was hospitalized in critical condition but has since recovered and is in a foster home
Osei faces up to 10 years in prison on the second-degree felony charge when she's sentenced later this year after pleading guilty Tuesday
She wasn't given bail in case she flees to Ghana where she lived before moving to the U.S.