You got this
I've managed to go something like 4 for 4 on picking cichlid pairs out of tanks containing groups of single species just on the basis of behavior. On the assumption that males display the most dominant behavior, I watch to see whom the alpha males alternatively persecute and ignore. Other males command most of their attention, and while females may not be immune from male aggression, seems they are generally tolerated in relative terms. So when I see individuals drift into an alpha's sphere and be tolerated, or notice a male swim past another fish to harass a second, I imagine the object of inattention to be female. Females also seem to a bit more tolerant of proximity to their own gender as even sub-dominant males are often concerned with hierarchy.
It's worked so far, biggest problem is netting out the designated females once the whole tank goes into panic mode upon introduction of a net.
Just trust that faultless feminine intuition Girl - you know, it's that thing you ignored when you agreed to head the CCA.