It’s occurred to me recently that a lot of artists utilize same sex children but i don’t think anyone has ever gone into in depth so here I am to attempt to fulfill a role that no one asked me to. YAY!!
 
To be fair, this only came about cause my non-brony friend brought up an interest point. I have a sterile male in my verse but he said it shouldn’t be an issue since I can just make him fertile with magic as I do with same sex couples. Cause why not? That got me thinking, how does the magic of reproduction work in Equestria?
 
My theory is this: Magic flows through all of Equestria and within the creatures who inhabit it. All creatures in the land have natural abilities, like a a unicorns magic, and pegasi’s flight or a dragons fire but we all know there are limits to ones natural abilities. Examples are Trixie and Sunburst when compared to ponies like Twilight and Starlight. They all have magical abilities but not at the same level. This means that even if one is capable of a task that comes naturally, like magic, some have either weak or nigh non-existent skills.
 
This is where reproduction comes in and it too is connected to the magic flowing through creatures. All creatures can reproduce but some can’t. This is something within them that can’t be changed, even with magic. Magic is powerful but not godly. Even if it was godly, there are rules to it. Discord, while capable of reality bending, has limits to what he can do, since even he can be depowered by either other magic (the changeling hive) or more powerful creatures (Tirek). Celestia and Luna are also weak to things, despite being, conceptually, the most powerful ponies in Equestria. This shows that magic has limits.
 
In most Next Gen universes, when two ponies or creatures of the same sex want to reproduce, a sex change spell is utilized, turning one of the couple into the opposite sex to create a child the old fashion way. We can assume that this spell will last as long as pregnancy is in place then the spell fades. The pregancy would have to be the limiting factor since, if the spell fades, the fetus would have nowhere to go and would just be floating in the stallions bladder or something. To sustain the pregrancy, which the point of the spell, the pony would have to stay a mare.
 
Sex change spells are, for various reason, temporary. They can’t be permanent and within the canon, technically not possible (Magic Duel) but who ever cared about that. Anyway, the way it works is that the spell will take the magic with the creature being changed and shift it to the opposite sex, basically taking what is already there and using it on the flip side. So a stallions virility will be equal to the mares fertility and vice versa. This spell can’t go on forever due to the strain it takes on the pony and can only go on for a single pregnancy. The pony would have to reuse the spell multiple times if they want a ‘permanent’ effect but doing so would mess with their bodies in way that might make it impossible to reproduce.
 
As far as I can tell, there are no spells that changes living creatures that are permanent. Nightmare Moon’s curse and even Discord’s had a time limit because magic fades and the spells grow weaker over time. Inanimate objects can be changed but only because there isn’t any magic running through it that can potentially get messed up but living creatures have a delicate balance. The magic is what keeps pegasi capable of flying despite their wings not technically being strong enough and what keeps dragons from burning themselves from the inside despite breathing fire.
 
These traits can be shifted about and poked at but not changed since it could have unforeseen consequences.
 
I can only hope I put this out correctly but please tell me what you think.
 
Also, the reason why Nova is here is cause she, being curious like her mom, would probably have studied this since magic is a curious but mostly untapped subject of study.