Dear Miss Snark,
How long should a writer wait for feedback from her agent? Is three months for a 65K-word novel on the long side? Under what circumstances would you take that long? Should the writer take that as a sign to find a new, more interested agent?
Patient... but not that patient
You've signed with her and you're waiting for her mark up to get a finished ms out?
90 days sounds like enough to me, but I've taken longer on some to my chagrin.
The thing is, stuff happens that sucks up time during the day (like making deals) and the weekend (like stalking George Clooney) and a manuscript mark up is (for me anyway) about 20 hours of time, if you're doing a full mark up, not just a read through.
If you've signed with the agent, call her up.
Ask her what her time line is.
You will either shame her into moving her lazy ass (me again) or find out if she's losing interest.
I'm not sure what "feedback" means exactly. Surely you're not waiting for her to tell you if she likes it?
Manuscripts sitting on the shelf "waiting" for whatever, are not revenue generators, and Miss Snark is an avaricious beast who prefers to earn and spend money like a drunken sailor.