YWCA
Girls have a program called Girl Scouts.
Girl Guides, which was later called Girl Scouts of the USA
Depending on the Girl Guide or Girl Scout organization, the leader of a small group of Brownie Guides, usually 6 girls, is called a "sixer". The group is called "Sixes".
The rules for the organization of a language is called syntax.
An organization is called a charitable organization. A person is called a philanthropist.
A group of girls is called "a giggle"
Girl Guides or Girl Scouts, depending on the country and organization they are members of. The international organization is called the World Association of Girl Guides and Girl Scouts (WAGGGS), although there are other scouting organizations which also accept girl members.
The organization that publishes "Which?" magazine is called Which? Limited.
They were the Plastics.
The Evil organization was called Broken Birch
Only one, Larxene, Number XII. Xion, "Number XIV", is a girl, but she isn't part of the Organization.
5000 girls are called Chloe in the UK.