M., your daughter is reacting to the news. She might be confused. start taking her to your appointments and talking about how she will be a big sister and have a little baby to hlep mommy with and how fun it will be to have a little one to play with. Check of books from your library about new babies in the family, believe me your librarian will have a large selesction to chose from. Watch what ever videos you can about a new baby as well...Sesame Street and Mister Rogers both have one as well as a few other well respected production companies... your library should have these or be able to get them through interlibrary loan.
Ask her pediatrician if there is any information that you can refer to. Take her to sibling classes through your hospital.
Make a playdate with a friend whp has a new baby so that is she has any fears she can slowly face them.
Buy her a new baby doll with a diaper bag, diapers, and accessories. You can get cloth diapers or make them out of baby washclothes if you use cloth and they sell wonderful baby doll slings for up to age five at hotslings.com
If you breast feed and do not feel strange about explaining that to your daughter (if she remembers nursing herself then), you can explain that you won't need to have a bottle to feed the baby.
This is a wonderful opportunity even during the frustration to help her overcome her anxiety without focusing on her mistakes so much that it becomes more progressive.