Ursula Marie Bowman, 39, is charged with simple assault.
Police were called to a room at the Red Carpet Inn along the 2800 block of Lincoln Highway East early Sunday for a report of a domestic disturbance.
Officers found a man in the parking lot who was bleeding from a stab wound to his left arm. He told police he had been staying at the motel with Bowman when she stabbed him after becoming angry over a text message on his phone.
The man refused medical treatment at the scene.
Bowman was arrested and taken to Lancaster County Prison in lieu of $25,000 bail.
A preliminary hearing is scheduled for March 13.