I had a long chat (argument) with Helen the other day about her query process. I thought I would post the gist here for anyone querying.
She reads queries as they come in. She gets 60+ a day. If she is interested, she will respond immediately. If she is not interested, she simply will not respond.
If you send in a query & don't hear within a week, assume the answer is no.
(I don't know how it works with partials. I would like to think she'd respond to those, but if you have sent multiple follow-ups without response, assume the answer is -- again -- no.)
She is very specific about what she likes in query letters, and it is generally not the format you find in "how to write query letter" articles. She wants to see that you can write a good query, telling her how you found her, a bit about yourself, and a bit about the novel in question. She does not want "hooks" or rhetorical questions.
I really don't know how I landed her as an agent. She must not have been so picky 10 years ago.