When they start darting away from their "safe place" as this is when I would normally notice them. Most of my spawnings of large cichlids were accidental (oscars, dempseys and a nasty flowerhorn cross), though. I know there are quite a few cichlid parents that take care of their fry- my l. hecquii and a. cacatouides are breeding colonies where fry are left in until juveniles are ready for trade in conditioning- which I have also done with convicts. In all honesty there is a lot of debate in many cichlid breeding circles about this very subject. I think that's why no one has really felt comfortable with answering this question.
I have no experience with breeding green terrors, so if someone dropped your breeder tank in my warehouse my first thing would be to observe parental behavior and research their known behavior (fishbase.org has an expansive research database).
Good luck!! Cichlid breeding is so highly addictive though, so be careful not to overrun yourself!!