Some nuts are toxic and so are some plants. This is a great site for you to check out ... I keep a list of all the toxic foods and such on my fridge. There is good info on all sorts of health issues. Just search in the search bar for toxic food or toxic plants. Everything is also printable.
Tree nuts in general are toxic to dogs. Peanuts are legumes, not "nuts" and are safe (peanut butter being an awesome great and perfect for putting in a Kong)
It is also a bad habit to let her chew things like that because even if you happen to have plants that are not toxic, A)not everywhere else will have safe plants and B) out in public, many people spray pesticides, fertilizers etc on the grass/plants which can be dangerous too