Hope this helps, from the girl side of things:
1. We freeze easily and much faster than you, so I vote for T&C. Brazil is warm, yes, but no place for beginners: huge shorebreak (even experienced instructors get mauled) and strong current on the ocean side and lagoons swarming with pros who make you feel like a bug for just daring to go near them (Toby is an exception)
2. It's so OK to teach your girl to kite! I don't understand the problem. Maybe I'm missing smth. But hey, If you get divorced over kiting, you were probably going to get divorced anyway.
3. In time, she'll change your style, may challenge you to do more fancy stuff that looks good in photo stream, and just knowing you are the role model makes you better, bigger, safer and more of a gentleman.
4. My honest advice is: once you teach her to kite your way NEVER EVER give into peer pressure and push her to kite someone else's way. That is really counterproductive! If there is anything we don't forgive is being a push-over and not having a syle of your own.
I think every kitesurfer should teach a girl to kite and commit to her safety for life. It might make the kiteworld a better place, less stressful and opinionated.