African fry and parents in the same tank

So I have a 55 setup and cycling right now with a goldfish, preseeded filter material, and live plants. It will still be a few days until I move any important fish in there, but I was wondering if I would be able to put my adult Pundamilia nyererei and 2-3 month old fry into that tank together? I know they didn't touch convicts of the same size, but hey, no one likes convicts and they probably taste bad. Would this be a good idea? I have 4 adults and probably about 50-75 fry at .5"-1".

The fry, so long as they are not mouth sized, should be OK with the adults. What are your long term plans for them? As they grow they will outgrow that 55G as that's a lot of fry and a lot of fish for a 55G tank. If you want to decrease the amount of babies you have there are some options too. You could split up the adult male(s) and female(s) for a while putting the moms in the tank with the fry and putting the males in another tank.

The older fry shouldn't be mouth sized, though there are the subdominant ones that grow slower... As foe my plans... I want to grow out the fry to show colors to verify the species is Pundamilia nyererei and not a hybrid or different Victorian species. And I only have one male adult now, and three females. They always seemed to take forever to eat the feeder guppies I put in there, so they aren't very aggressive. I could try to convince my wife that we need to keep a 30gal for the fry, but I don't think she's gonna go for it. Lol

My only other options are to sell the fry as pure Pundamilia nyererei, or to cull them.

Unfortunately, you can't be sure that they are pure by their appearance as they mature.  Some hybrids will look like one parent or the other and not a mix of both and that will be especially hard to determine if the species are similar in appearance.  If you didn't see them spawning or if they aren't in a species only tank, there's that possibility that they aren't going to be pure.

They were sold to me as Pundamilia nyererei, but I haven't been able to confirm their identity. They've never been with other Africans, so I know the line is pure on my end. If certain color patterns show, I will be able to confirm their species, as well as the collection point.

Okay, I misunderstood. I hope the person you got them from was as responsible as you are with them.

If you have them all in the same tank just put a bunch of rocks in a pile for them to hide in if they are attacked just in case.