Fully comp is expensive, but sooo worth it, IMO.
I had a 15 y.o old corolla as my first car when I was 17. I bought the car (in absolutely immaculate condition) outright for like $1500, but I still got full comprehensive insurance on it (in my mums name with me listed as a driver, so it was cheaper). Just as well too, because the car got stolen and completely trashed beyond repair by the kids who stole it... Like alot of 18 year olds she probably thinks she's indestructable and it'll all be fine... and she probably will be fine, but anything can happen.

Good on you for doing up a budget for her. Hopefully she will listen to your advice and try to stick to the budget.