She should 1) do some research to see what type of things are being particularly looked at - like how to write the essay she needs.
2) check out all the veternarian programs and apply to all that look decent.
3) to realize that it's harder to get into vet school than med school, but if she scopes out what sorts of things they are looking for in the essays.
4) sign up for a masters program in biology while she's waiting (I know this works for med school, not sure about vet school).
She might not get to go to her first choice program, but if she's as good a student as you say, she should be able to get in to a program.
What is her undergrad study emphasis? Is she an animal science major, or majoring in some other field. Usually, the vet schools admit about 50 students per semester. They get like 500 applications. What is the cut for Large Animal/Small Animal vets?
It is a tough competition. She needs to go back to the committee and talk to them and find out why and then reapply next semester. When I was at Kansas State, one of the top Vet Schools in the Nation, some students had to apply 2-3 times to get in.
It is also based on personality. Vet work is not for the timid. Also, straight A's is no guarantee of success.