Western doc in general don't hv an idea what brings abt the miscarriage, as they don't treat the body as a whole, if you notice. Some pple looks healthy but hv difficulty to conceive, it could be due to the womb being "cold" according to Chinese medicine. A lot of factors affect pregnancy/health like our emotions, the environment, pple around us, diet etc.
When the body is under sudden tremendous stress, it could induce premature birth. Diet also plays a part, cold foods, or too much fruits(esp tropical fruits) or yin(weakening like eg. sugary foods) food consumed during pregnancy can weaken one's condition. If consumed in moderation is ok but not excessively.
She is getting better cos there are no more news of pple getting pregnant, but if there are news, she will start to feel down again. To be pregnant again and not having problems during pregnancy will not solve her problem, how is she able to ensure that problems will not recur? If it recurs, won't she be more unhappy and disappointed? There are a lot of things that we can't really control, things do happen suddenly and it's important to be prepared to avoid any shock to the body esp when one is pregnant. Lack of rest and stressful relationships do affect pregnancy. I had a stressful marriage for both pregnancies ,and my second pregnancy is the worst.
Pls tell yr friend to stay happy and positive at all times even before she is pregnant. It will help her a lot,esp during pregnancy and she will hv a happy baby too. Ideally, it's to be emotionally, mentally and physically healthy. However, it's not easy to achieve in our modern stressful society.