@Sharkexpert12
What Serenata said is correct, and this is said concept art:
Sorry about image's size.
@SF
Others already thought of it, and there's actually even fanarts depicting this scenario (or, at least one, the one I saw), but some other people also hypothesised that the crown can't just fall off, and would need to be intentionally removed. Now you can just choose which option you prefer.
Now @BugDevil
Just adding my two cents: My view of Bowser is of someone who doesn't really care about their gender and would be fine with either, so as long as he likes his appearance as "Bowsette", he would just go with it. Thus, whatever gender the viewer choose to perceive Bowsette as, would be valid.
It was a while ago and my memory is kinda crappy of when I remember it (highschoo and stuff) but I do remember a fem bowser image from what feels like 8 years ago might have my timeline mixed up cause drugs... but i probly saw it on neogaf or something it was a really rough sketch in typical tpose postion. And yes i talked to some guys from back in the day they also vaugely remember the thing enough to vaugely remember it once exsisted but was probly nuked from orbit by Nintendo at the time. To be 100% clear I cant find definative proof on these images after looking into it and even asking some contacts I still have. So just assume im off my nut and have no idea what im talking about. Before you ask no I know noone from Nintendo of Japan and to just add in a bit more most publishers and development studios are frankly untrustworthy so never take their world on anything unless its backed up with proof.
The meme is gold tho cant remember the last time a popular meme involved this level of creativity so however it started and whatever its roots it dosent matter. Its probly my bad for not doing any digging on the matter and just working off a vauge memory. So just ignore my ramblings and enjoy the meme.