If your helper breaks expensive stuff is it fair to deduct their salary? The helper broke a $2000 vase which I said to be careful

Oh dear. Sorry to hear about your vase! I wouldn't be too hard on her if this is her first time. Mistakes happen (sometimes at a cost)... but she didn't do it on purpose (remember that). Tell her to be mindful and alert from now on. If it happens again, then perhaps you can let her know that you will have to cut her salary for it.