Modern Marionette

Pretty girl.
Watch her twirl.
Notice her glide across the floor.
She has beauty. She has grace.
Have you ever seen such a determined face?
She can run. She can jump. She can soar. She can juggle.
Easy is the look she swings with ne'er a sign of struggle.
She enchants all with her smile, her grin from ear to ear.
I wonder how she would ever wipe away a tear?
Does she sing? Can she laugh?
Why doesn't she ever sit and relax?
She can spin. She can leap.
I am sure she never sleeps.
Fast is her climb. Hard is her fall.
How quickly and sprightly she springs back to her all.
She doesn't bruise. She doesn't break.
She only continues with her gait.
She turns right. She swings left.
She presses forward without a sweat.
She can bridge upon her back. She can fall upon her knees.
Her movements remain constant; her balance is a breeze.
Her poise is always elegant. How does she put on such a show?
She does not need a breath 'cause it's effortless, you know.
Who is her manipulator? Why is he unseen? How does he hide from human eye?
Bending in curtsy for her crowd, she performs a grand good-bye.
She does not speak. She does not shrink as she exits in puppeted grace.
Her master calls. She must obey. Her resignation once more to this obligatory pace.

Do you recognize that girl? I think I know her. I just couldn't see all the strings attached.