Part of a farmer's repertoire includes fishing if all requirements for it are met. Despite whatever coaxing you may do to keep her farming and away from the ocean and the fish, the thought will still cross her mind that as a farmer she should fish, at which point she'll run away. And I speak from experience here... I have a villager myself in an established village that I tried dunking repeatedly to get him to fish. Unlike a villager who dislikes berries yet can be coerced to forage, this villager will have nothing to do with fishing and now is so traumatized that he's running amok in fear that the big hand in the sky will make him fish again. =P