Im no expert by any means however my wife likes taking pictures as much as I like reef tanks
I would say based on talking to her about cameras and lens etc. That the canon rebel t1i is a really good camera to start out the hobby with. Really from what she has told me the camera itself is important and you want one with a really good sensor in it but the secret for taking great pics is lighting/ flash and a really nice lens. Depending on what your style of photography will be that is where you will want to invest some cash. Keep in mind though taking good pics of fish and corals is different than most other things you take pics of. I have found using the lighting from the tank when the room is dark gives me the best results.