How strong is hard to say. It depends on your player character and how you play the game.
What works are Lust Potions. Seven Corrupted Lust Potions were enough when my PC "attacked" Vicoria the last time. Potion strength - at least those your character is drinking - are influenced by Int. So you should maybe approach her with ten of those Lust potions, just to be on the safe side. Please save before you approach her.