Had a good friend whose son had the exact same condition. He went through several surgeries to correct it, and the parents had to be very careful with him and foods that he could eat. He had to go through a couple of surgeries as he got older to make sure the esophagus was stretched enough to grow as he grew. He is about 8-9 and lives a normal life and if you did not know him when he was born you'd never know he had any issues. He has had no complications from it other than just having to be careful with eating and more frequent checkups to make sure he isn't experiencing any problems. It is a serious condition but it is not something that should keep her from any normal life when she gets older. I will keep your family in my prayers, because they will have a long road ahead of them.
I've heard about this condition too and while not very common I don't think it is very rare and there is a lot of experience and documentation regarding correcting it.
