In Pokemon swsh, all of the "special spawns" (the ones that appear on the map) are all predetermined, with their gender, IVs and level all already calculated for all of the games worldwide, all of them that spawn in the same spot are identical for everyone, and these can be identified by flying out of the wild area and then flying back to that spot and if it spawns straight away after coming into the vicinity then it is a special spawn (another way to find these out are to knock them out and then waiting, they only respawn after a certain period of time). All of the milotic for some reason have the predetermined gender MALE for EVERYONE, this means no matter how much you want a female Milotic from the wild area special spawns, if there isn't one for everyone, it isn't there (I haven't checked so I'm just basing this off of the question), you can get a female if you breed for a feebas and it is a girl and then evolve (breed with a ditto).
Hope this helps