could be wrong but I think that in the USA the AOC ranges from 14-17 according to jurisdiction but visual images, even if utterly imaginary and showing only one person with no explicit content or nudity, are banned below 18, 19, and 21 by the same jurisdictions. Canada has even stricter laws on artists' depictions of people below 19 although the AOC is 12 in some of its jurisdictions. Marriages in North American sub-cultures such as the Mormons and the Travelers often involve "marriage" between females 11-14 and males 25-85. I do not believe that below the age of say 24 or 25 true consent can be suggested in cases where the age difference is more than 2-3 years.  The age for voting in the USA is 18 and the age for drinking alcohol is 21 with an exemption for persons in military service as young as 17!

http://www.coolnurse.com/consent.htm