When I hired the 1st maid, I and my husband agreed not to lock our room. Because we think that if we locked our room, it seems not trust the maid. However, the maid stole our money in the safe. Then, we fired her.
Now, we both agreed to lock our room. Because she stays alone (of course, with my baby) at our home for about 10 hours, actually it's a big temptation to her.