I seriously, seriously can't understand the comments along the lines of "but she's the Queen! But you have to be born to it!".
In past times people thought you had a special calling from God to be monarch, that you were a special person because you and only you could do it, and God had chosen you for it. (Not in Scotland, actually, but that's another story...) But surely we don't still think that do we? We don't think that by accident of birth a particular family are the only ones that can do the job?
And I'm sorry if you don't think its a job, but it is. Heads of State all over the world carry out their job. Most don't believe that they are the only ones that can do it, them or their offspring. Dare I say it, but promoting your family members into positions of power and influence is often though of as un-democratic.