。
She burned her right hand.
Literal
She [topic-は] right hand [object-を] burn-did.
やけどする ('to get a burn') is a noun-verb compound: やけど ('burn injury,' from 焼け+処 'burnt-place') + する. The kanji is 火傷 — literally 'fire-wound' — but the kana spelling is far more common. Note the framing: in Japanese, you 'do a burn' on a body part, with the body part marked by を rather than the burn itself; English would say 'burn one's hand,' Japanese says 'do a burn-event involving the right hand.' This pattern parallels other body-incident verbs: 怪我をする ('get injured'), 風邪をひく ('catch a cold').