Just remember, sometimes females will go missing because they have decided to sit on a nest. One day they are gone and then a few weeks later they come back with little puff balls. I don't think this happened to mine, but you never know.
That is if they don't get taken by a predator first. Depending on the predator load in your area, more often than not Hens don't come back once they disappear because they've gone broody on a pile of eggs outside the safety of the coop or covered pen, unless you've located the nest and are able to protect it some how, long enough for her to hatch out her keets...
This is my hugest pet peeve about Guinea Hens... following/hunting down the broodies (and losing them to predators before I can find the nests)