Hello, and welcome to the Parrot Forums family!
From the looks of it, she seems to have a few stress bars. As SailBoat mentioned, feather condition is a reflection of the past few months. All stress bars indicate is that, at the specific moment in time that particular feather was forming, your girlfriend's greencheek experienced something of a stressor. This might have been a major change in environment or circumstance, a traumatic event, an illness, or a less than ideal diet.
All that said, however, there really aren't very many of those marks at all. If any of those causes match anything that has occurred, addressing them should head off the development of more stress bars.