I had similar problems before and my agent advise me that i should charge her for damage subject to each item not more that $300 and the total sum deduct for each month not more that 1/4 of the salary (according to regulations). Also, you need to record down the damage and ask her to sign for your record purpose to avoid situation that she would 'make' a case to labour or immigration that you act wrongly. If you charge them one or two times, they will be more careful. You need to be more stricter on this otherwise the situation will become worse.
for valuable things, you better state in writing the costs of these items, and write down the conditions in the event they break or damage it, they have to pay the full costs and ask them to sign. If in the event they break it , apart from the stated amount of $300 for each item or a maximum of 1/4 of $3,270 for each month, you can state a case to the labour department for deduction of the exact amount from the salary; one whole sum or a portion of the amount for each month.