Translation:She wants me to prove that I only love her.
i asked sum1.... appearantly u can also switch between only using moi or chi since they both mean only.... and when using moi usually people end the sentence with ma thoi ...."mà thôi"... i dont quite get the ending yet but they seem to use alot of ending for sentences to make sentences sound more polite... O.o eg: "anh chỉ yêu mỗi mình em mà thôi" (where anh is the bf-pronoun and em is the gf-pronoun)
Good question, perhaps it is a structure like "chỉ... mỗi..."? Never heard that one before though >_<
Year 2019 here...I consulted a native Vietnamese speaker and she told me that "...chỉ yêu mỗi.." is used for emphasis. Sometimes the same word is used for emphasis like "luôn luôn".
Edit: BTW, three years is kinda long time to await an answer.