Obviously, she should have put "Of what town were you mayor of?" as the security question. And "Nairobi" as the answer!
Folks, You can enter ANYTHING in as the 'answer' to your password backup security question. Even this: "%*'mCC~/5Ff-+@)n", or this: "+d~!?b9B'4|=". It works just like a password (any character, upper case, lower case, etc). They don't care what you put down. In fact, they don't even know.
Anyway, Yahoo, and whoever else uses this password backup security question feature, really needs to give a more serious warning about it. I have a feeling they will now.