。
She sang Japanese songs for us.
Literal
She [topic-は] us [to-に] Japanese songs [object-を] sang for-us.
歌う ('to sing') with the benefactive ~てくれる marks her singing as a kind act done for the speaker's group. うたう written in kana here softens the formal feel — kanji 歌う would be equally valid. 'Japanese songs' (日本の歌) often points at folk or traditional songs (民謡), enka, school songs, or contemporary pop, depending on context — the bare phrase doesn't specify, leaving it to context.