I corrected all occurrences of "childrens" (about 500 of them). Most were corrected to "children's" but some were "children". There are several cases where "Childrens" is used in an organization's name. Here's a list:
"Feed the Childrens", a song by the fictional band Limozeen
I corrected all occurrences of "Womens". There were about 200 of them, 90% of which were "womens" and 10% "womens'". There was even one "womens's". Here are some exceptions: