I wish we could have Saturday morning writing sessions at the Huntington every week and lead gloriously exciting lives away from Oneonta for the rest of the week! But alas we'll have to blog it instead...
I agree with Ben - there will be a few people who have it planed down to the week but most people will be like I want to be a writer this is what I'm supposed to do, right? I think that you should go with the piece they accepted you on and take a sampling of other stuff. Just grab it and go. You might use it, you might not, but at least you can say this is where I'm coming from and it's a pretty good chance that it's got at least a thread of where you're headed.
Use your adviser! Tell him/her right up front that you're considering the mystery route but you love literature and is there a more meta-literature road you can take or should you pick a genre. That's what they're there for - to help guide you - plus it's your first session broad ideas are expected. If it was this time next year and you were still like ummm, well maybe, then you'd have a problem. Until then don't put undue pressure on yourself. You're gonna rock it!
I'm also thinking about recycling for the quirk challenge. Finding Alice is a non traditional story with a dark twist and reading their published novels list that seems to be the road to take. I also thought maybe Pan would work here, but I wanted to ask you if you'd care if I took the idea back? I know we never actually worked on it, but I did throw it out there as a trilogy idea and if you still want to work on it together that's totally ok!
I'm here if you want to pro/con sample lists!
P.S. You are not an old lady! I totally want a garden :) Also I'm thinking about adopting a cat. Thoughts?