Geophagus Surinamensis: Breeding surprise

I picked up 3 of these, small, all female, non aggressive, non digging, impossible to breed (according to LFS) Geos 6 months ago or so. They have been in my main Discus display tank, getting big, fighting, digging up everything and generally being beautiful d1ckh4ads. Now they have a big swarm of fry! They are as far as I can tell taking turns to hold them in their mouths while one of the others digs up a plant, and the other enforces the no-go zone in the tank for the other fish - who at the moment are grudgingly confined to about 5% of the tank. Let’s see how this progresses...