。
She's scared of dogs.
Literal
She [topic-は] dog [object-を] shows-signs-of-fearing.
A small but important grammatical detail: when the adjective 怖い ('scary / scared of') becomes the verb 怖がる ('to show signs of being scared of'), the particle marking the feared object switches from が to を. So 犬が怖い ('dogs are scary [to me]') but 犬を怖がる ('she is afraid of dogs'). The ~がる suffix is what Japanese uses to describe other people's emotional states — speakers don't directly assert someone else's feelings, they describe the visible signs. Use 怖い for yourself, 怖がる for everyone else.