Sometimes Guinea Hens will share nests, but usually if given the choice most Hens prefer total privacy. A predator won't care if the nest is a single nest or community nest, it's all a free meal to them (and they will be feasting on both Hens and eggs).
But yah, I agree... to avoid any losses it's a wiser choice to gather the eggs and incubate them (or stick them under a broody chicken) if you want keets, or dispose of the eggs if you don't... be sure to break up/destroy the nest and chase the Hen back home to the coop/pen (if you have one). She will most likely start laying again in a week or 2 so you will either have to keep her penned 'til she lays her daily egg each day (and get her back in each evening), or do the nest/egg/Hen hunting thing all over again. This can go on until late Fall when the daylight hours shorten, the Hens start molting and the breeding/laying season is finally over for the year.
If you decide to leave your Hens on their nests to brood and hatch their keets on their own then I highly suggest putting on a suit of armor (lol), gathering keets into a box as soon as the hatch is over, and then luring the Hen into a pen with them where she and the keets can stay alone until the keets have grown and feathered out some, and are better able to keep up with Momma, plus able and agile enough to avoid any possible aggression from the rest of the flock (and it's a good idea if the rest of the flock can see them, but not get to them during this time... this helps with integration later). Not only are Guineas not great Mommas most of the time (they can end up leaving some of them behind, getting them wet and chilled etc), sometimes the rest of the flock will try to kill the new keets because they see them as threats/intruders. Not always, but it does happen. Sometimes the flock helps raise the keets tho (like a bunch of nannies)... this all depends on the particular birds/flock tho. But IMO if you want the Hen to be able to successfully raise her own keets, then it will need to be in a well controlled environment with shelter and food and water for a while. I'd make sure you are around when you decide to let them out and allow them to integrate with the rest of your flocl, and be ready to gather them all up again if things go the wrong direction.
Some have had decent luck with building a predator proof enclosure around the Hen and nest (setting it down over her at night works best)... but sometimes that back fires. Guineas hate change, so the Hens can go bonkers, scatter eggs everywhere and then pace and squawk until let out... and in the process all the eggs go cold and die. Moving the Hen and eggs usually results in her abandoning them, so i never recommend that, tho some have done it. Guineas are not like broody chickens in the zombie broody that must sit on eggs aspect at all, and if their nest is disturbed they just leave and start over somewhere else.
Best of luck, whichever route you take.... Welcome to the breeding/laying season!
