Oh Flower!! (why on earth? etc) Mind you despite my being a married adult at that time, I'd never met as far as I was aware, a single other person who was T1, though a couple of elderly neighbours/friends of parents were known to be T2. My mom knew a T1, round about her age, hence she knew it didn't kill you etc etc. In fact a couple of weeks before, she'd told me I had all the symptoms of T1, to which I'd replied Gawd - don't be so pessimistic mother! - to her credit, she never once said 'I told you so!' LOL
I really really missed my best mate when I was diagnosed - she'd literally just gone off on honeymoon, touring around Italy for 3 weeks, the Thursday evening before I'd been standing on the windowledge of their new house, helping her hang her lounge curtains. She couldn't have done anything of course, but 2 heads etc when you know you both generally think the same way …...
A problem shared ….. does actually help even though it doesn't halve it cos it's better for mental health. Hence - you, mum, really have to let your DSN (she's your DSN as well as your daughter's!) know everything whether daughter wants you to, or not. Plus you WILL have to tell her school, ask her to consider that aspect.