Will keep her in my thoughts and prayers....
My wife is a thyroid cancer surviver.....for the last couple years we have been dealing with this...I try to be there for her, but its hard to put yourself in that persons shoes really.
All you can do is be there for her the best you can.
Modern medicine is amazing and I am sure your daughter will be fine. Sounds like they caught it in time, like with my wife.
Make sure she is seeing the specialists available in her medical network.....we were seeing doctors at first and then found a specialist who was like night and day for us.
Through it all, just remember that God has a plan.....we may not be able to figure it out at first, or ever...but there's a plan.
Prayers going out.