Her application is already pretty impressive. I would advise against retaking ACT - a 34 solidly meets the bar for all the schools mentioned and she is better off investing her energy elsewhere.
Seeing as Cornell is probably the top school by far with a food science degree, I would advise she applies ED (if she is sure of her interest). This would boost her chances and, with a stroke of luck, she could be done with the whole application process by December!
Good luck