Hi,
she may not be having a miscarriage at all...
when i was pregnant with my youngest ( now 14), i had alot of issues. Just to kinda tell you what i went threw, maybe it will help!
I went threw a very scary process.... when the baby got large enough to hear a heart beat, my dr's told me there wasn't one, and told me that they were going to do an ultrasound, and then prep me for a miscarriage. I was mortified.
I went threw the ultrasound.. and the tech kept asking me how far along i was etc... then he showed me what was going on... the baby was at 6 weeks of age, but my water sac was at 10 weeks of age. when i went to my dr. he explained to me that it was just a fluke of genetics, but it was going to make it difficult to moniter the baby's growth, etc. So, threwout my pregnancy with her, they never heard a heartbeat, and i didn't show until my 8th month, and i never felt her move. 2 months before she was due, i started having contractions 2 minutes apart, that never progressed into hard labor, as my dr. explained to me, it was false labor, due to the water sac being 4 weeks farther along then the baby and they put me on med's to stop the contractions. I stayed on bed rest and the med's til 2 weeks before she was due, and then my dr told me she was far enough along to deliver. In the delivery room when my sac was broken, it made the delivery very hard, because there was so much extra water to deal with and it made it hard to get ahold of her and make sure she was ok, and to make sure there wasn't a rupture or anything for me.
But now, 14 yrs. later she is a very healthy happy child, she has no disability's or learning problems, nothing of the sort. So, it may not be that she's having a miscarriage at all, it may just be a fluke of genetics. Now as far as the alcohol goes, that I can't say really anything about, as I don't drink, but it might be something to bring up to her dr. I hope that maybe this has helped with your situation. Good luck!
R.