。
She bent over the child.
Literal
She [topic-は] that child [genitive-の] above [target-に] body [object-を] bent-down.
身をかがめる ('bend down, stoop, crouch,' lit. 'bend one's body') is one of the productive 身を~ family of body-set phrases — 身を引く ('step aside'), 身を寄せる ('lean against, take refuge'), 身を投げる ('throw oneself'). の上に ('on top of, above') marks the position. The whole captures a tender protective moment: bending over to check on, comfort, or whisper to a child below.