No, no, CHACHI was the one that said they had multiple siblings. At least I think so. It wasn't my idea at least. And as for the monarchy and how it works, ask Chachi. It's possible Kita was chosen to be the heir just because she was the best choice of her siblings. I dunno how Chachi wanted hierarchy to work in the wild Pokemon world.
And since Kito's past has little to no relevance to Rooke the Trainer's story, I don't have much desire to use it. It's Chachi's story, she just let me have a cameo in part of it.