They didn't like to you and I can't sex them either. Need a better photo. Check the ventral fins and males should be longer, but that is not guaranteed.
TBH they don't look like the same species to me. The yellow one on the bottom is definitely a female, but it looks like an agassizii. The other one, I'm not sure of sex, or even what it is, maybe laetacara curviceps?