Thirty-seven-year-old Denise Carlson, of Riley, pleaded Tuesday in Topeka to conspiracy to distribute Oxycodone and Oxycontin.
Prosecutors are recommending a two-year sentence.
Carlson admitted conspiring with 31-year-old Christine Swanson, whom she met at Mercy Regional Health Center in Manhattan, to obtain the drugs after learning Swanson's sister was a pharmacist at the Salina K-Mart.
The hospital says neither woman was working as a nurse at the time.
Swanson pleaded guilty Monday to conspiracy and obstruction in exchange for the government's recommendation of a three-year prison
Both women face sentencing on June 13. Pharmacist Katherine Surowski is set to go on trial June 14.