If your daughter is positive for antibodies, than she is Type 1. Type 2 is not an antibody condition; antibodies are actually a more definitive diagnosis of type than c-peptide. I am a little surprised they just tested GAD65 as the other antibodies are more typical of straight type 1 and GAD65 of LADA/1.5, but the bottom line is the same. I agree with Sally that you and she need to focus on her care now. Your daughter has a lot to learn about managing her diabetes and I suggest she get on a website with more diabetics managing their condition, and more young people. Private message me if you want a url. I also highly recommend the book Using Insulin by John Walsh.
I would guess that her presentation (not overweight, and presenting with acute symptoms of diabetes) and her age would be more typical of typical of type 1 diabetes. Type 2 diabetes usually develops in older people, who are typically overweight and it develops over time, not so acutely.
THere is also a type 1.5, which is an autoimmune type of diabetes (like type 1), but develops in older people (not children). Treatment for this may also be insulin, though oral meds may work for a while.
I recommend at this stage you don't question the diagnosis, but work with your daughter to get her blood sugars under control with the insulin and lifestyle measures, and lots of home testing and coordinating with her endo to optimise her meds. This is very important to prevent complications. The HA1C of 10 is very high. They prefer to see numbers less than 6 and the ideal level is about 4.7.