My daughter, now 11 was diagnosed with type I diabetes a year ago. The diabetic team were brilliant and visited her school within a week of her diagnosis. She was at primary school then (the primary school were absolutely fantastic with her), but has since moved to secondary. The diabetic team again said they would go in if we wanted them to, but we felt a lot more confident in what we were doing then, so I gave the school a booklet I got from
https://www.diabetes.org.uk/Guide-to-diabetes/Schools/Diabetes-in-schools-resources/
I'd say it's really important for someone to go into school to start off with because in the beginning you don't really know what you're doing and you need people around your daughter who have some basic training and know what your daughter needs to be doing in case she forgets.
I also work in a secondary school (not my daughter's school) and we've had several visits from the diabetic teams from the two closest hospitals for diabetic students who are not newly diagnosed, so I'd say diabetic teams in our area routinely visit schools if parents want them too. I'd push for a visit. Your daughter needs to feel happy and confident that she can manage her diabetes in school and she is much more likely to feel this way if she is supported by her diabetic team. Good luck