Usually when I do this (with any cichlid), I put a female in the middle compartment, and a male on each side.
It is usually obvious after a while, which one (if any she selects), or rejects.
With cichlids, just because you have a male and female, doesn't mean they are compatible.
With my female haitiensus, she took her time, killed a few males, but finally decided on one, and mated with him constantly for many years.
Sometimes just throwing a male and female together, doesn't cement a strong enough, or lasting bond.

I also like to use a divider that allows scent cues, and current provided by the movement of their bodies, and be assessed.

