Simplify the following text for a Grade 7 native English-speaking person.
Original: John Marshall , one of the excavators at Mohenjo-daro , described her as a vivid impression of the young ... girl , her hand on her hip in a half-impudent posture , and legs slightly forward as she beats time to the music with her legs and feet .
Simplified: John Marshall , one of the excavators at Mohenjo-daro , described her as a young ... girl , her hand on her hip in a half-impudent posture , and legs slightly forward as she beats time to the music with her legs and feet .