I don't know your specific situation but I can tell you that I have a friend who's ultrasounds and amnio showed that there was something "off". They went to see geneticists and had constant ultrasounds and doctors visits. They were first told the baby would be born with a heart defect and would need surgery, then they were told that his heart would be fine but he had a brain disorder.
Guess what? He was born perfectly healthy and still is three years later! Sometimes a scare is just that, a scare.
After what you have been through with your first daughter, I'm sure you are scared to death for your new daughter. I won't tell you not to worry, that is impossible. But I will tell you that you can do this! You can be this baby girl's mommy no matter what heatbreaks or joys it brings to you! I can tell you will love her just the way she is no matter what - I will be thinking of you and your daughter.