Axolotl Cloacal Questions

[ClaireBear]

Okay so last night my Boyfriend and I were admiring our 3 little axies as usual, when we noticed our oldest/biggest on Bruiser's region was much bigger than before!
No I've been doing a bit of googling this morning and don't reckon it's a prolapse or anything unhealthy.
He/She is swimming as normal, eating as normal, very responsive etc.
I'm wondering if this could be a sign of full sexual maturity and Spermatophores or Eggs coming our way?
Seen no Spermatophores yet so I don't know if Bruiser is a female and has got pregnant without us ever noticing!
Marshmallow and Salsa both have small Cloacal regions so I'm totally confused!
Been trying to get a clear pic since last night but no success!

 

[JodieBromilow]

Your oldest will be a boy if it has a large cloacal area its defo a boy and smaller cloacal area means their girls this page will help you scroll down and you'll see the pictures hope this helped
Axolotls - Biology