This probably was the first time she got to chase down something with feathers on it. I would follow this up with up an intro to birds and guns. Take her out in the field and toss a clipped wing bird and let her chase it down. Don’t be surprised if she tears it up or wants to eat it. The whole idea is prey drive. After she has had a few sessions of chasing birds you can add the gun. Start off by having someone fire the starter pistol say 100 yds away when the bird hits the ground. If the dog shows no reaction to the gun, move the shooter in closer. Do this until the shooter is next to you when you throw the bird. Repeat the process with a .410 and then with the 12 gauge. By doing it this way you are making sure the dog is not going to have any problems with guns and loves being in the field. The key here is not wrapping in any other training into the session. For example, I don’t enforce any obedience commands or worry about retrieving at this point. Use a checkcord so the dog can’t run off with the bird. You can then use the checkcord to gently coax the dog back to your area. The dog will learn that if it gives the bird back to you it will get to chase it again. Now even though we are not working on retrieving, we will encourage the retrieve and hold if the dog is performing well. At the end of this training you can start to use flyers and have the dog flush the bird. After the dog has flushed a flyer, you can now plant birds in the fiels for the dog to find. Now we have a dog that is bold in the field, loves to find birds and has a positive attitude with guns.
Now we can work on the retrieve. Make a retrieving alley by using a side of a building and some garden or snow fence. what we want is a narrow alley where the only escape route is behind you. Now when you throw the retrieve the dogs only option is to run back to you. Keep using the retrieving alley until you are positive the dog is going to bring back whatever you throw.
Birds are way more fun to play with then bumpers. Don’t worry if after you come back from the bird training your dog doesn’t pick up a bumper. A few tosses while out exercising and it will be back in the game. Now when tossing bumpers you can do as Red Lab said and start working on “hold”. It sounds like you are off to a good start. Have fun, Don.