Nancy,
Just logged on after a bit of an absence. Wow! I am thrilled that she is using her head right now. Huge.
As to the vitamins and all that... well, I am just old enough to remember my sisters just going ahead and having babies (big age difference .. my first niece was born when I was 4!). They ate what they wanted, didn't eat what they didn't want, pre-natal vitamins were unheard of ...and, between them, they nine healthy infants who turned into nine amazing adults.
Yes, it is ideal that she does whatever she needs to do for her baby..but her not drinking is way more important than vitamins at this stage. I hope she does this after she sees the doctor, but don't sweat it.
And, Star, seriously...we can't speculate about this. There is no "recipe" for a difficult child. Sometimes kids of difficult children break the cycle (read The Glass Castle by Jeannete Walls). It happens. It could happen here.
Dash