Where do you place the apostrophe?

Today I was writing a letter and I could not remember where to place the apostrophe in possessives of irregular plural nouns. I wanted to say the children’s Easter Egg hunt will be moved indoors due to the inclement weather.If the word is an irregular plural like children (from child), women (from woman), men (from man), you place the apostrophe after the word and add an “s” just like for singular nouns like The horse’s mouth.

This link explains the rule.