I’m sorry but I can’t find the article I was thinking of where it said molars may need to be re-trimmed after about 6 weeks, but I know I did read it and it was a good, scientific article.
I have a rabbit that have had to have molar trims twice, 6 months apart. There is a member here who has her bunny’s teeth checked and trimmed every 3 months, and not that long ago, when she took him for his regular check-up, he had developed a molar spur that penetrated his tongue so that part of the tongue had to be surgically removed. (The bunny hadn’t shown any signs of pain or reluctance to eat.) So rabbit teeth grow very fast and as you know, they grow all the rabbit’s life.
So you should see your vet again about her teeth and do what you can to make her eat as much hay as possible, because that’s about the only preventive measure you can take yourself. The role of (dietary) calcium in dental disease has been (and is) discussed, but it seems the jury is still out on that one.
Here is another article on rabbit dental problems, it’s by the HRS (an approved source):
http://rabbit.org/dental-disorders-in-rabbits/
You will find lots more if you google, because this is, unfortunately, a very common problem in pet bunnies.