Leave It

Awesome! Success
Time to up the ante just a tad.
Try it out in a different, slightly more distracting environment, or with an even more delicious treat being thrown, or another object of desire.
Train for success, so you want to increase the difficulty just a bit at a time--you know your dog best.
Are there any real world, everyday temptations where you can be reasonably expect her to listen and prefer the rewards of a successful "leave it"?
As in, live scampering squirrel--very likely not--dried up peice of 10 day old toast--maybe yes.

Thanks! We've upped the ante in both regards. We've moved outside on the deck to increase distractions. I've also increased the treat. I was throwing kibble and rewarding with chicken. Now I'm throwing hot dog and rewarding with hot dog.

There are LOTS of things I want her to leave! Hahaha. My goal is that she'll eventually be able to walk calmly in the park without reacting to other dogs or people. Preferably ignoring them. Part of it seems like fear but a bigger part seems like barrier frustration because she likes dogs. We haven't done any work in the park in two months. Her trainer said to not take her around triggers until her basic obedience is solid. She has some triggers at home in the yard and she's fairly desensitized to those now. Right now she's listening to a neighborhood dog bark with no reaction - which is an improvement.

Are there currently any items which your pup takes interest in which you never want the pup to possess? If so, train with those items and reward with your food treat and praise. The impulse control/wait training you are currently doing is a good start but the confusion which can be created by using leave it items such as kibble and other food items which your pup is allowed to eat at other times will make it more difficult down the road when you truly want your dog to leave an item for real such as mushrooms, dog crap, dead animals, plants, many items in the house, harmful foods for the dog, etc. There is no release from a leave it command.