Andrea Lawton, 47, entered a plea in Montgomery County Court to one count of burglary and one count of criminal conspiracy to commit burglary, the Philadelphia Inquirer reported Tuesday.
She faces up to 20 years in prison on each count.
First Assistant District Attorney Kevin Steele said he plans to seek the maximum sentence for Lawton.
"This is a priceless work of art," Steele said. "He (the owner) is incredibly hurt by what has occurred here."
The bust, by French sculptor Jean-Antoine Houdon, has been recovered but it was damaged during the theft and is currently being repaired at a New York City museum.
It was taken Aug. 24 from the home of Bryn Mawr lawyer George A. D'Angelo.