I think instead of buying, look for options whether your relatives and friends have unwanted clothes/shorts for her size. If yes, then ask them for a few pieces for your maids.
I will only buy maids clothes on speical occasions so that she won't think we are carrot head for her to chop! I bring my maid to CK, Pasar Malam (Bugis area) to get those special occasion clothes.
You will be surprised some maids even choose clothes which she wants/likes to wear, whether those given by relatives/friends or purchased from outside.