I don't know her general response time, but for me it was aobut 3 months after I sent her a full.
My personal experience was that I sent the ms out in May (I think) and I didn't hear anything until August, when she emailed me saying she loved the ms and was taking it to a meeting at her agency to discuss its marketability and stuff like that. A couple of days later, she emailed me to say that the meeting had gone well and could she call me? We talked on the phone later that day and discussed comments people had made at the meeting, like things I might want to revise and things they really loved, and then she asked me about myself before offering me representation.
After that, working on revisions with her was great. I'd had about 5 or 6 people critique the ms before I signed with her and she had suggestions that no one else had thought of. Plus, she's just generally nice and easy to work with.