。
She's not afraid of snakes.
Literal
She [topic-は] snakes [object-を] is-not-afraid-of.
怖がる (こわがる) means 'to fear' or 'to be afraid of' — the ~がる suffix turns the adjective 怖い (scary) into a verb expressing behavioral signs of fear. The polite negative 怖がりません states she shows no fear of snakes. Japanese uses を with 怖がる (object marker) rather than the が that 怖い takes, because ~がる creates a transitive verb.