Firemouths
Firemouths like all cichlids need a choice to choose a mate. Just because you have a male and a female doesn't mean that you will automatically have a breeding pair. One of the easier ways to get a breeding pair is to add 2 more females into the mix.
The male will choose his mate. Then remove the other two females before the pair kills them. Volia! breeding pair.
If the pair you have however are already a breeding pair and just aren't breeding. The other thing could be that they are too stressed from the Breeding JD's. Who I know from experience get quite nasty when breeding. So they just aren't.