。
She said something strange.
Literal
She [topic-は] strange thing [object-を] put-to-mouth.
口にする is a doubly-handy idiom — its primary sense is 'to say, utter' (literally 'put to the mouth'), and a secondary sense is 'to eat, taste' (to put into the mouth). Context disambiguates entirely: 名前を口にする = 'utter a name'; パンを口にする = 'eat some bread.' Here 奇妙なこと ('a strange thing') makes the speaking sense unambiguous. The phrase tends to mean a single, deliberate utterance — not a long monologue but a specific remark or admission, often one the speaker considered before letting out.