Writing Prompt: Who’s dancing and why are they tapping those toes?

Source: http://thinkwritten.com/365-creative-writing-prompts/

She taps her toes. 1, 2, 3, 4. The music isn't right. Not this song. It's just not right.
Her fingers skitter across the glass screen of her phone to try another song. Nope, not right either.
Again she taps for a new song. Not this one.
One more time.
Yes. This is the one.

The slow ebb and flow of the music pulls her from her stool onto the hardwood floor. Her faded pink toe shoes thump against the oak slats of the dance studio floor as she whirls around the studio. She feels the music deep inside her, guiding her feet and arms into beautiful, elegant shapes. Years of practice has led her to be this comfortable in her movement. The light fabric of her skirt flowed behind her with every step.

She faces the mirror, chest heaving as the music ends. Her reflection smiles back at her, and a movement catches her eye. Behind her in the studio window is a little girl, gray eyes twinkling with glee.

The little girl raises herself up and tiptoes in front of the window, hands high above her head, attempting to mimic the dancer's elegance. She trips, but smiles, looking at the dancer with the hope and inspiration of one day dancing too. The little girl's mom pulls her away, arms filled with shopping bags, to the next storefront. Her little hand waves to the dancer as she disappears from view.

The next song begins and she looks at where the little girl had stood, tapping her heel gently to the beat of a youthful and rapidly flowing piece.