Children's or Childrens' Centre?

[BookcaseFullofBooks]

I often get confused about where the apostrophe should go in instances like this.
I've been using the latter form because I thought it was a case of the centre belonging to several children.
Please tell me I haven't been writing it incorrectly on a public forum

I won't tell you then.
Children is already plural, surely.

'Children' is a group word, and so it is classed as singular (like people, or crowd, or audience). So it's children's. Sorry!

Children's
Women's
Men's

etc.

What iggi said! :)
1st one's correct as 'children' is already plural.

But Girls' School is correct because Girl is singular?

Oui.
School of the girls.
School of the children.

So it would be children's school and girls' school?

I wasn't taught grammar at school, can you tell?

Ah, thank you