Hmm, I'm not sure. What size are they? If they're less than almost 6 inches it can be had to tell. The smaller is colored more like a female but has a longer ventral (bottom) fin. Sometimes with CA & SA cichlids the smaller weaker fish will "try to look like a female" & less threatening to a larger stronger cichlid of either sex. Do they fight or lock lips?
They both are colored like females, except for the smaller 1's bluer lips...that says male to me. A female may beat up a smaller weak male...
It can help to arrange tank décor so they are not always in each other's line of sight. Real or fake plants, wood, rocks etc may help.
What other fish do you have? I see a tail of some biggish fish in your pic...What size tank are they in?