Boone stopped the proceedings and questioned King at length about her involvement in the robbery.
Assistant State's Attorney Duane Gigeous said King not only drove the getaway car that day for a first cousin but she helped plan the robbery and shared in the proceeds.
"Trooper 1st Class Kevin Lewis of the Maryland State Police stopped the car and found King was the driver," Gigeous said. "She had $250 in her bra."
Gigeous said the cousin told King that no one would get in trouble.
Witnesses at the bank identified her as the driver of the car that popped its trunk and allowed the bank robber to get in after the robbery, which netted $5,193, Gigeous said.
There were no injuries in the 2:46 p.m. robbery.
King, then 17, of 121 W. Bethel St., had been charged with armed robbery, conspiracy to commit robbery, felony theft, use of a handgun in a violent crime and carrying a concealed weapon.
Those charges were dropped in exchange for the pleas.
King was allowed to remain free on $20,000 bond pending sentencing.
"This is a very serious offense. This court is getting tired of drug dealers and stickup artists," Boone said.
Defense attorney Ed Button said King is pregnant and has a child, now 1, who was 2 weeks old and with her during the robbery.
The first cousin, Asa King, is a convicted murderer who escaped from a New Jersey prison nearly two years ago.
Asa King was tried in U.S. District Court in Baltimore several months ago on a bank robbery charge but the jury couldn't reach a verdict. The proceeding ended in a mistrial.
Asa King remains in custody for the October 1995 escape and to resume his 99-year sentence for murder in the Bayside State Prison, court records said.