I got Gonzo when I was 13 too.. I had never taken full responsibility for any dog up until then. I was getting into a lot of trouble at school and out of school, and our Rottwieler of 7 years had just passed away. I wanted a dog, and my parents wanted me to re-direct my..um..energy .. so we got Gonzo. I really wanted a German Shepherd, but my parents wanted a Border Collie because we had 2 when I was growing up and my Mom grew up with them, and I also liked the breed. I have full responsibility of him, and it has really made me a much better person. I realized he completely depended on me and he needed a LOT of work with obedience and behavior, and it helped me to focus on more important things in life, things that are EVEN more important than boys and friends and shopping! -gasp-... I could no longer blow off my parents and stay at friends houses and go to late parties, because my doggy needed to be fed and played with and exercised ^_^

Anyway, I totally support you! As long as she's really into this, and you get her to commit to it (with a contract like you mentioned, or something similar), it will probably work out really well. I would definately let her do a lot of the work in researching breeds, finding breeders or rescues, and organizing what supplies she wants. It'll make her feel a lot more like this is HER dog, SHE needs to prepare for it and she needs to work for it. Also include cleaning and exercising duties in the contract .. and try to get her to clean up after, walk, and feed Casey for a couple weeks to get her used to it and make sure she knows what she is getting into. As far as a good match with Casey, it completely depends. If she has a tendency to be picky about dogs, rescue would be the way to go so that you can introduce her before-hand to the dog and make sure they get along. A laid-back male of around her size might be a better choice than a small dog... but, again, it totally depends on the individual dog. Casey might prefer a more playful dog her size if she likes to play with other dogs.