Well, the eating grass is instinct from when dogs were wild and ate things they couldn't digest and pass....same with cats....and is not really a bad thing, tho not very pleasant. Part of the problem might be puppy is teething and is chewing everything.....ask at the pet store or your vet but I think they make toys that are just for teething puppies.
My pit used to also eat EVERYTHING ...like my house but I just got vinegar and put it on the house where she chewed until she stopped then I also stopped....but grass is good for dogs if their stomach is upset they usually eat that
Get her more toys to chew on, rope bones, sterilized beef bones, and a kong will do the trick. You have to keep an eye on her, they eat everything until about 1 1/2 years and can get really sick or even die if they eat the wrong thing. I call my puppy captain destructo!!!!