By Elizabeth Daley

PITTSBURGH (Reuters) - A Pennsylvania woman convicted of helping her husband rape her teenaged daughter in an effort to conceive a baby that the woman could raise as her own was sentenced to 15 to 30 years in prison on Thursday, her lawyer said.

Misty Machinshok, 33, of Wilkes-Barre pleaded guilty in January to charges including rape, assault, endangering the welfare of a child and conspiracy.

Prosecutors said Machinshok was unable to have another child and wanted the 15-year-old girl to become pregnant so she could raise the baby.

They said Machinshok assisted in the rape by pushing the girl onto her husband and suggesting the best positions for getting her pregnant.

Prosecutor Nancy Violi called the crime "the most heinous" she had dealt with in 14 years on the job.

The rape came to light when one of the girl's friends alerted a teacher who called police, Violi said.

The girl was raped more than once in 2013 after the couple met through a website called onlinebootycall.com, Violi said.

Gary Machinshok, 29, has pleaded no contest, cooperated with prosecutors and testified against his wife.

He also was charged with sexually assaulting Misty Machinshok's younger daughter, age 11 at the time. He is slated to be sentenced on Monday.

Misty Machinshok's lawyer Mary Deady would not comment.

Violi said both victims are in foster care.

(Reporting by Elizabeth Daley; Editing by Ellen Wulfhorst and Eric Beech)