Imagine that, a teenage girl losing focus. Who'd of thunk it.
My son does the same thing. I have to pull him aside and re-focus his energy, and stop talking about whatever is taking his mind off the task at hand. The only words out of my mouth are; Stabilize, Elbows locked, Arch hard, Sit back, Spread your knees, Sit on your balls, Drive your head up. It gets boring but some days it's needed.