With her size and age, if she does get sick, things can go downhill pretty fast. HOWEVER! She might be perfectly fine. It's good you're learning but try not to over worry yourself. You'll be more stressed then needed.
Like what buffy512 said, what's done is done. As you keep an eye on her, make sure you have some "emergency supplies" on hand. Like nutrical, emergency vet numbers, etc.. Starting her training early is not a bad thing. But again, with her age, size, vaccines, etc.. it's better to keep her contained. If you have wild animals (deers, foxes, etc) that's able to get onto your back yard, then I think you should be more careful. Make sure you're right there with her in case she tries to eat/roll something she shouldn't. Like bird poop...
Lastly, don't stress yourself out too much. She can probably sense it...
