Heh
No I like this name too. I think John did the name a favor by writing so many songs about Yoko that to his fans her name became synonymous with an exclamation of joy, love, and comfort. But it really doesn't exist outside of this Lennon vocabulary and there's no reason to pretend otherwise by giving it a middle name like Charlotte or something.
I think if I were naming a kid Yoko her middle name would be Hair Peace.