Why you should use a focus keyphrase only once

I read the Yoast article ‘Why you should use a focus keyphrase only once’ after the warning popped up while I was writing a post.

The problem is, is that my website is called babies and children and I was using that as the key phrase and mentioning the website name in the post I was writing (basically a merry Christmas from babies and children post) It was really the only keyphrase I could have.
Although, yes I’m not that bothered if that page ranks, I don’t want it to rank over say my ‘about us’ page!
So, the question is, if the key phrase is something you can use multiple times, what should you do?

Regards
Paul

The page I need help with: [log in to see the link]