These soft-grown Agaves are often a challenge to identify, but I believe you have Agave multifilifera there.

Possibly Agave parryi

Close enough. Perhaps A. parryi ssp. neomexicana. Very pretty plant.

Wait it sounds like you have Genus and species already. Are you looking for a variety or subspecies? I would say Agave parryi looks like a good id:). It's definitely not A. parryi truncata or neomexicana as you've stated. That leaves you with A. parryi v. couesii, A. parryi subsp. parryi, and then a variety of A. parryi subsp. parryi which is A. parryi v. huachucensis. There's also this one called A. parryi 'Estrella'. I don't think it's A. parryi v. couesii. The leaves seem to be thinner on those. This is where it's hard to id though because the mother plant of your babies from what I can see looks like has been living a cush life. Like it gets water and not tons of sun. So you're not seeing the true structure of the plant. Plant that Agave in all day sun with little water it will look very different. That's why I think you're having a hard time at iding:). Along with myself;). I wouldn't commit to any varieties or subspecies quite yet. Growing conditions can totally change the look of your babies. I would acclimate to all day sun and give little water than it will be easier to tell. I think:). If you have the space put them in ground. I would just stick to Agave parryi for now. Like I've said you've got a Genus and a species that's good. Don't get hung up on other names. Just keep it simple for now.