[Teresamag]

You should take the baby to a vet immediately so he can assess it and see if she also has a cleft palate which often goes along with a cleft lip. If so, it's possible she may be able to be raised with tube feeding and/or special bottles or it's possible she may have to be put to sleep if the cleft is too severe. If she has a cleft palate she may not be able to nurse and could aspirate any fluids she does get.
If your baby is one of the very few that has a cleft lip without a cleft palate she still needs to be seen by a vet because she may have trouble latching onto the nipple to nurse. She will need help to prevent starvation and/or dehydration
Can you post a picture of her lip?

Teresa