Palancole you are absolutely right. No one has evidence of her exact age at marriage nor if there were others who married 6 year-old girls. I bet the hadiths that say she was 6 years-old when she got married were just made up to pervert the image of the Prophet and Islam simultaneously.

But as it says in the Quran: Their intention is to extinguish Allah´s Light (by blowing) with their mouths: But Allah will complete (the revelation of) His Light, even though the Unbelievers may detest (it).