Silence is golden… and ignoring her will driver her nuts until she finally leaves you alone.

Or you can take the more spiteful approach and threaten to pour some capsaicin (hot pepper extract) in her food. Make sure you have the bottle when you make this threat as she will probably test you and you will need to actually do it to prove you will. From then on whenever you want her to shutup you can just alert her that you will do it again no matter what punishment you might get for it.

Or if you have some photoshop skill (isn’t that taught in pre-school now?) you can just make a picture of her doing something awful. Then you simply need nothing more than to remind her of the picture and she will cooperate. This method should only be used for extreme cases because though she will be quiet, she probably will hold a grudge for a LONG time where as the previous method will only make her not want to eat your cooking.