I finished my first novel about a month or so ago, and have a couple of published authors in the same genre reading it for me. So far the feedback has been all very positive, however I am still waiting on one author... But I'm getting impatient, more from the excitement of having finished than with her. Would it be rude or unwise of me to start submitting to agents before she gives me her feedback?
However long the author is taking to read your manuscript, you'll probably be waiting ten times as long for an agent to read it, and then twenty times as long for a publisher - so think of it as good practice! One month is really not a very long time, even though I know it seems an eternity when you are busting to send out your manuscript. But I can't overestimate the value of patience if you wish to be a successful writer.
It is worth waiting a little bit longer because if she comes back and says, 'This is great overall but this particular sub storyline is completely implausible', you'll be regretting that you sent it out before having a chance to fix any problems. You only have one shot at agents reading your manuscript - if we read your manuscript and you then call and ask if you can submit a revised version, the answer will be 'no'. Not because we don't necessarily like your manuscript, but because we don't have time to read manuscripts more than once for anyone other than our clients. (The mathematics of manuscript reading is: 1 full ms = approx. 8 hours of reading; time to read during average working week = 2 hours; ergo, time to read 1 ms = 4 weeks, if we're lucky. The figures are much more bloated for publishers). And all that was a slight digression but it leads me back to where I started: it's worth waiting a little bit longer.