It’s not just the practical suggestions here, it’s the relief of being amongst people who understand and who also have Type 1. It’s a very lonely place to be soon after diagnosis. Knowing you’re not alone is a massive boost. Soon after I was diagnosed, my nurse put me in touch with someone who had Type 1 (no internet or forums then) and that phone call was a major boost for me - someone who got it, someone like me.
You’re right not to overload her with information now, but there are a couple of books about Type 1 that are popular here and will be helpful in the future:
Think Like a Pancreas’ by Gary Scheiner.
And
Type 1 Diabetes in Children Adolescents and Young People by Ragnar Hanas (ignore the title - it’s great for adults too).
Supporting her by making sure she has lots of hypo treatments in the house (Dextro tablets, Lift glucose shots, jelly babies, etc) is good. Also, help/support her in beginning to count carbs. She’s on fixed doses for meals at the moment but soon she’ll learn how to adjust her mealtime insulin according to what (how many carbs) she’s about to eat. Also, be patient. It’s a huge emotional shock and people can be depressed, tearful, angry and quite emotional. This is normal.
Make sure she has the phone numbers of her tea and knows when to call them. It does gradually get easier.