She is young, so this may well be part of the problem and controlling it is imperative if she isn't to turn into a bully.

I hate the word top dog and dominant. A truly dominant dog, or alpha dog is actually rarely physical - they simply are and other dogs recognise that. In fact, they are usually the calmest dogs. What you describe is more bullying (don't get me wrong, it's not a criticism and I'm sure she's lovely ), but because owners think it's dominance they allow it as natural behaviour. It rarely is, it's more likely she hasn't learnt how to behave around other dogs. This is partly because she is young, excitable and puppyish. But definately control it as otherwise it will become a learned behaviour.