I adopted Ben at 10 months of age. My father in law adopted his dog at the same time. The one major difference - she was 6 years old at the time. We both went to basic obedience classes together (that's all she's done, and boy does it show
). Ben and I continued on and will be getting ready to compete in obedience in the fall.
I think it's all in what you put into it with the dog. Thelda (father in laws dog) was very bored by the time we graduated...she's had enough and we worked around it. Changed it up a bit to challenge her.
There will almost always be a 'standing around' period after classes when people ask questions of the trainer and socialize with each other....I think that's when the dogs can make friends with each other, but when class is in session, it's time to work, and it's up to you as the handler to make sure she knows it.
Most of all - have fun!!!