She helps her mother prepare breakfast in the kitchen every morning.
Literal
She [topic-は] every-morning, mother [subject-が] kitchen [at-で] breakfast [possessive-の] preparation do [object-の] [object-を] helps.
母が台所で朝食の支度をするのを手伝います — the nominalized clause (母が...するの) is the object of 手伝う ('to help'). を marks the activity being helped with. A warm domestic scene.