Nicki, that's awesome! I don't think you should have a problem!
Rusty (our old lab mix) was from a shelter (he was older - almost a year - when we got him) and when we brought Tucker home, he was perfect with him. We had Rusty first (for about 6 years), so its not really the same situation, but just to give you a little example!
I LOVE shepards, but I think in this case I would go with a lab mix. They're generally very laid back and they tend to not mind being touched/pulled on/barked at whereas shepards are a little more sensitive to stuff like that. But just go with your gut (and heart)!
