There are a total of 4 different dialogues that will have effect on this trophy unlocking. Below is the listing of dialogue that you got to say in order to unlock this trophy after calling her stupid:
Tell her that her mother is overreacting.
Tell her to buck up
Tell her maybe
Tell her don't be stupid. (trophy unlocks)
If you missed this trophy for any reason or you chose the wrong dialogues, then you have to play the game all over to get this trophy. Replay Scenario will not give you this trophy.