Cara Blewitt, 30, of Oakville, Connecticut and her husband, Seth are accused of holding up a TD Bank branch on May 28.
Police said they held up a Dollar Tree store near the Bangor Mall the following day.
In both cases, Seth Blewitt is accused of pointing a sawed off shotgun at employees while demanding money. All while his wife waited outside in the getaway car.
According to the U.S. Attorney's Office, Cara Blewitt pleaded guilty Wednesday to aiding and abetting bank robbery and something known as a "Hobbs Act Robbery."
She faces up to 20 years in prison when she's sentenced at a later date.