I'm sure no expert but in my very limited experience-You're making want to get a a third dog! I am about due for a new pup. There is nothing like a well trained dog that YOU trained that flushes a bird, you hit it with one shot, they mark the bird and proudly strut bringing it back to you!
Gun Dog Supply has some great mini and mid sized canvas dummies. The minis are really small, so your girl might have already outgrown them. I use the minis the instant I bring home a 7-8 week old pup. I usually start in a hallway so that the pup has to go out and can only come straight back to you. Always keep the sessions short so that they end wanting more! Tons of praise to build confidence and excitement.
Another thing is I only ever throw dummies for my dogs to retrieve--no sticks or tennis balls etc. The dummy should have a special place in the dogs mind--it means both fun but also business as they get older.
Let us know how she's doing
- No sticks. My dog can play 'tug', but ONLY with his rope toy. My wife knows this. Anything else and the toy must be carried gently and released immediately on command ("release!")
- Mine LOVES his soft bouncy blue silicone ball that comes with a ball-flinging stick. I can throw that ball what seems like nearly 60 yards and it bounces and skitter... the dog nearly 100% can catch it in the air on the first bounce. That quickness makes him a machine at bringing back cripples and he loves the exercise. Of course he must RELEASE his ball immediately. We drop on the ground but you could train to the hand, of course. But Dog knows it's MAN'S BALL, not his ball. So does the man! (or woman. My wife is onboard with this training, too.)
- Once he learned to swim (a bit of a process of going in with him gently several times, letting him learn at his own speed, and then meeting some other Labradors that would jump off the low pier... he just needed to see the big boys doing it and he was all game to go. First efforts were pretty funny, but he learned. Then retrieving the dummy from the water was the best summer time game ever. I've dropped pheasants into water more than a few times and over a creek more than a few times, and Labradors are smart. They love to problem solve and retrieving over a creek is a great game, too.
-Tennis Balls... sometimes we're around untrained dogs that are "Getters and Stealers". In that case, there is another tennis ball in the pocket. Also.. sometimes a ball is lost. Another thing we practice is a well slobbered on tennis ball tossed into the thick grass in summer time to practice "Find It!" A big orange dummy is too easy!
As I said, I'm no pro at this but I do have a pretty amazing dog when it comes to a Flushing Retriever. His weakness is.. it's like murder trying to hold him back when he knows where a bird is. Our solution is to hunt the rough country where that's not an issue. He's 5 now and.. it took 3 1/2 years to get the Puppy in him scaled back! I can't imagine he would be any use at all in a duck blind or boat- he's gonna bring back the decoys no matter what.