I really don't have experience in this area, but I did want to comment and wish you well. Some of the older posts say that vomiting is normal with pregnancy, but I am unaware of how much vomiting would be a sign to seek medical attention. I would think if she cannot keep anything down she would be depleted fast, so I would keep a close, careful eye on her. There is great advice here at YT and I am sure that an experienced breeder will contact you shortly. If you don't hear from anyone by chance, I would contact her Vet just to be on the safe side, especially if she continues to vomit and not keep anything down. Nutrical works wonders. Good luck and keep us posted.
YorkieProud