It's Official. She's here to stay!

Well, we've finally put in the adoption papers for Lucy and called our references to tell them - and you'll start seeing plenty more posts about her (and Grendel) for a long time.
We went to our first obedience class with her this week - aside from two pee incidents (she was trying to tell us), she did great. She seems to have learned the sit command (no speaking, just a hand gesture) and is progressing with 'Watch Me' pretty well. However, Linda (our instructor) already gave us a little private coaching on how we might want to tackle her more challenging issues - her mouth. She's definitely a mouthy dog, and while a good knee to the chest works when she's running at us in the backyard, it's the gentle nipping on city streets that I really worry about. Everyone in class is great, and they recognize she's young and needs to learn. Not everyone in public feels that way, and more often than not, other dog owners (and their dogs) are far scarier for how they behave when approaching us. How about those great folks who let their terriers run at the far end of a retractable leash directly at Lucy full speed? Or those dog owners with very large 'oh, she's friendly' dogs who let them run off-leash everywhere - and then can't call them back when they make eye contact with our 'she will kill you' dog? I cross the street when approached by another person with a dog, or I give them a very wide berth. A child? I'll cross the street or make Lucy sit (with my hand tight under her collar) until the family's far past the 6 foot reach of her leash. No matter what, we will be good ambassadors for this breed - it's our responsibility. But I tell you, when that guy came up to Todd and said 'it's not the breed, it's the owner,' I really feel like someone should have said, 'no, it's the other dogs' owners.'
And Grendel? A little older, and definitely requires some protection from her, but he's doing just fine. They're striking a balance and have even worked together to get food out of a food puzzle.