Its not too easy to tell the sexes from your pictures but it looks like all 3 are females. They all are rather big in the belly regions. It may be that you are feeding your fish overly well in which case fish No 3 may be a male. I would suggest if you wish to breed these fish go buy another 6 and pick out some slimmer and some fatter fish and yoiu will be almost sure of them breeding if you have the conditions right.
BJ