seeing as reptiles and birds born in the same egg are monozygotic (i.e. it happens when the fertilized fetus splits into two seperate fetuses, as opposed to seperate eggs, which most egg-born animals are), it would mean that both dragons would be the same gender. with peril's brother not living long enough to know anything about gender, it would stand to reason that peril is canonically trans, even if by accident on tui's part.
of course dragon biology could be different, but they seem to be extremely grounded in real life animals, all of which are identical twins when monozygotic.
disproving this is the fact that peril has too much fire and ember too little, making them unidentical, but the prevailing theory dragons have for this is that it's due to an abnormality during gestation that causes the birth (or in this case-hatching) defect.
tune out now if you don't want any more Biology lesson but this stuff is fascinating and i'm gonna talk about it anyway
birth defects can be caused by genetic factors, but it's likely that it was a factor outside of this that caused it, as there is a very similar birth defect in humans that is not genetic.
twin to twin transfusion syndrome (or ttts) is when, put extremely simply, one twin receives blood and oxygen through the other (known as the donor) instead of directly from the mother, causing the donor to have decreased blood volume, while the recipient has too much.
this is a clear parallel to ember (the donor) and peril (the recipient), except with fire instead of blood. possibly whatever compound the dragons use to produce fire is transferred through the blood, meaning peril has a naturally high level while ember's is low.
ttts is NOT genetic, and is instead caused by random chance during fetus development.
read more about it here: https://www.tttsfoundation.org/medical_professionals/what_is_ttts.php
anyways i wanna know what other people think! the evidence i've seen seems to be rather conclusive in my opinion, but you might disagree, and i'd be interested to hear why!
don't be rude on this thread! everyone is entitled to their own opinions, whether peril is trans or not! transphobia won't be tolerated on this thread, however.