Guinea matings happen very quickly, I wouldn't be surprised if you didn't see it. I am surprised your guinea male allows the rooster to mate with the guinea hens. Chicken/guinea crosses are rare, but can happen. I would expect you to hatch most or all pure guinea keets.
As already said, you can't force broody. If they have been in that pen that long and not gone broody, I would not expect it. You can try offering various nesting locations to see if they find one they like better. Some people have used wheelbarrows or large tubs partially filled with straw, some have used hay bales piled so there is a little cave for the guineas to nest in. But they definitely will only go broody if it is a place that they feel is safe, secure, and secluded. I make absolutely no predictions as to what YOUR guineas will feel meets those requirements, however!
Do you know that the eggs are fertile? You probably want to make sure the eggs are fertile before putting a lot of effort into encouraging broodiness.