multivitamins and iron for your sister, but don't let her take too many medicines, it sometimes has bad effects for neonates.

i think most of the meds on the market here need prescriptions, and since your mother isn't here and you can't bring her to the clinic to see docs, you aren't left with much to buy for her. the drugs in china are much cheaper than in america, and they are of the same ingredients, so buy them when you will be in china, saves bunch of money for you too! good blood sugar control is the key, so make sure she diet and excercises, and check her blood sugar often.