Thank you, that's helpful! No guidelines on the website about how long to wait, but I've heard three months elsewhere, so I guess I'll just resign myself to not knowing for a while longer...to answer your questions: it's a little complicated? This agent contacted me three years ago upon reading a story of mine in the Adroit Journal because I said in my bio that I was working on a novel (which ultimately turned into a play and is not the novel I'm waiting to hear back on). In those three years, I have sent her everything I've published, and last year I sent her a full short story collection, which she loved but said she couldn't sell. Because half the stories featured shared characters, she suggested I turn it into a novel...so I did...and I sent it mid-January, and now I'm waiting. She took a month with the short story collection, so I assumed it would be the same wait this time, but I guess not! But anyway...since she has spent three years waiting for me to send her a novel and invested a lot of unpaid time into my work, it feels wrong to try anyone else before she's given her decision, and because of our history, I'm would imagine she knows that I'm giving her the first look. But I don't know for sure.
