How to Double-Clutch?

Ok, my female laid 13 beautiful and fertile eggs on June 6. Right now, she is opaque for her post-lay shed. She has been eating 5 small fuzzies per meal, and digesting each meal completely within a day or so and defecating within the second day. So, I've been feeding her pretty heavily. Partly cause I want her to bulk more than she was before the first clutch, and secondly I need to make room in my freezer for a new order of fresh mice. =P

My question is, how do you know when (and if) she is ready to ovulate and lay again? Is there a set time-frame I'm looking at after her post-lay shed of which I should introduce her to the male again?

Or is this just a wait and see kind of deal, as to whether she ovulates at all? Do most females require mating a second time, or do they retain enough sperm to fertilize the second batch of developing ova?

Any people with experience with double-clutching, make your words known!

Far from scientific, but

When your female has put her weight back on, (usually will have shed again) pair her with a male. His reaction is a pretty fair barometer as to whether or not she's ovulating or receptive. I don't usually double-clutch, but that's how I did it successfully before. And I've never had two clutches from a season when I didn't pair her up again, so I'd think the likelihood of stored sperm making a second clutch would be remote. More remote even than her laying eggs the following year when not paired up, which happened to me once. Best wishes.