I have to agree with Kelly. If you can do it - go and observe different instructors. We got started this summer as a fun thing to help out a boxer friend who is starting her own training center. It was outside, Gypsy was having fun, but we needed to find an indoor place. So I found a 4 week class that was starting right when our outdoor sessions were ending. The teacher of the 4 week class was very unfriendly. There were several times where she set Gypsy up to fail. I don't think she liked the fact that we had not been in her beginner class, and I'm not sure she likes boxers much either.
So, it was on to another training center for her current class. Tonight we finish our pre-novice class and have already signed up to start novice next week.
If you can't go and observe the classes, try and at least talk to the instructors. Tell them you have a boxer, see what kind of response you get. Gypsy was slow to start out on the contact equipment, but now is pretty good about doing everything.
Good luck, and keep us posted on how Lily is doing with it.