I agree with the lovely Mamashack, they don't look particularly squared off to me either.
Now, about this whole "breeding" & "letting nature takes its course" thing.
Livebearers have loads of fry for a reason. They take zero interest in rearing their offspring, and its often the parents that eat their own fry. Therefore, they produce loads (circa 30 each month or so), so that some will survive.
Mammals, on the other hand, take a huge interest in rearing their offspring, they nuture until the young are able to care for themselves. But then you know that, you are a mammal yourself.
The issues come when we mammals project our mammalian instincts onto a different class of species, in this case fish. Sometimes, we try our hardest to ensure that every fry survives, because we don't like to think of a baby animal dying. So, we ensure that they don't die. Which gives us 30 new fish. But then, a month later, another 30 fry are produced. Well, we've got to ensure that they all survive, too, don't we? So then we have 60 fish. And then, another month along the line, another 30 fry are produced , so we have 90.
Hold on a mo! You've got two females. So actually, in 3 months, we have 180 fish. And in 4 months, we've got 240 fish.
It's only at 4 months that you can start to think about rehoming them - people want to buy mature fish, and any LFS who agree to take them won't be able to sell fry, so they will only take them at about 4 months.
Let's be generous, and assume that you have an LFS who will take your sub-adult fish off your hands on a regular basis, you still need to have the spare tank space to house 240 fish, and the time to care for them properly.
OK, now let's consider what happens if you can't rehome all of those 4 month old sub-adults. They are starting to reach reproductive maturity too. So instead of 2 females, you've suddenly got maybe another 15 (ie half of the first batch of fry). So instead of 60 fry every month, you are going to be looking at something in the region of 500 fry every month. And then next month, another 15 females reach maturity, so that's pushing 1000 fry every month, and so on.
Can you cope with that?
Ultimately, it's your decision how you maintain your tank. Clearly, there are other options, the main one being to get a few hiding places into the tank, in the form of plants. That way, a few of the strongest, bravest, fittest fry will survive to maturity. Remember, it's not "cruel" to allow fry to be eaten, it's what has happened every day in the wild for several million years, far longer than humans, or even mammals as a whole, have existed.
Good luck!
. I have a netted breeder box--waiting for the clear plastic one with slots in it to come in.
