Hi,
My Gemini is the same way. She's just about 10 mos now and she's very hyper and playful. She barks constantly when she wants to play or if one of the other dogs has her toy. She jumps up on us and nips when she's excited. I don't think this is aggressive behavior, but it definitely needs to be stopped--just imagine her acting like that when she's 2 or 3 yrs and much bigger. I suggest you get into a puppy class soon; the socialization with other dogs and owners will be wonderful for Zoe.