2q's Sharing eggs/chicks and how many clutches please?

You've been very lucky! Usually when two broody hens are in the same nestbox, they constantly try and pinch each other's eggs and often those eggs won't hatch because they've been out in the air longer than under the hen, so can't develop properly. Or the chicks are injured or killed in the hens' enthusiastic attempts to kidnap them from the other.
If one or the other goes broody again and you want chicks, it would be better to seperate her from the other and let her get on with it on her own. I would also recommend that you get unrelated eggs to put under her rather than her incubate her own as any resulting pullets would be related to the cockerel and could lead to all sorts of genetic problems further down the road if he mates with his daughter..

As for going broody, I have a Speckledy go broody early this year and she's broody again now. I'm trying to break her of it as she's a terrible Mum, but there's no set times a hen could go broody.