The reality is when little suzy turns 12, her parents need to sit her down and say 'Little billy, who has always been kind to you and you are best friends with? You have been arranged into a marriage with him. You will marry when you both come of age.'
she'll scream 'But I don't like Billy that way, I like Johnny!'
At this point you can try to explain to her that Johnny is single mother spawn whose father is in prison, regularly shows complete disregard for the law even at a young age, is flunking out of school, has no skills and is so retarded he broke his leg last summer jumping off of buildings for no fucking reason.
I can already tell you she'll respond with some variation of 'You don't know what true love is!' which is retarded, what does a teenager know about love.
Or you can tell her to shut the fuck up and that she'll be disowned and kicked out of the house if she doesn't comply, and then spank her if she keeps complaining.
The latter method is much more successful.
Some women can follow this on their own. Some people are geniuses. Most people are stupid.