Donna, Chutz and SJ have good advice here!
One thing you have to remember, I know it's very hard, but being worried about something you can't control is very overwhelming and makes you very anxious, try not to worry too much!! I know it's SO hard because you don't want to see your daughter in pain. I see what my parents go through with me, and I can see the hurt in their eyes! Though, one thing you have to remember, is it's going to be a LOT harder for you to handle then them! Your daughter will get used to it, to a point of it being a part of life! I got asthma when I was 7, and boy, that was harder for my parents than me!! LOL! I got used to carrying the inhaler, and taking the daily meds, and hey, it's a part of my life, though a PITA sometimes, it keeps me from suffering! And that will be the case with your daughter too, I'm sure it will bother you more than she! Not that I'm trying to make light on the situation, but to help you understand that it's not worth making it harder on yourself, it's not good for you, and your daughter will sense and feel it too! My parents worrying, makes me more upset, I don't want to see them hurt, but they don't want to see me hurt! So, a lot of times, I try and hide it around my parents, but they see right through me, and my face, which is always wrinkled from pain, LOL!
Also, remember, just what Chutz and SJ were saying, it will be worse later in life, than now, it's great that they found this now, and not down the road, it could make it harder for the back to straighten! If they use the device, it gradually straightens the back, if I'm educated correctly, it puts gently pressure, like braces on teeth, to straighten, so as she grows, they will gently pull the bones into correct positioning! So, try and stay calm, I know, it's VERY hard, but you, and she will get through this! Keep us posted on how things go!!
Good luck to you, your daughter, and all!!