My Ginger went through three levels of PetsMart classes (and what they teach in those three levels do overlap, so ask your instructor if she is ready for the next level), then we switched to Focus classes at Allen's Kennels, then to agility classes. So you can and should sign her up for more classes. A 6-8 week class is a good beginning, but it is only the beginning, in teaching a puppy. Personally, I really enjoyed going to classes with Ginger, and if I hadn't purchased a computer in 2004, and start spending so much time on the computer, I would probably have taken many more classes with her. It is something that I now regret. It is fun.