I wouldn't say "usually", but it is not that unusual. There probably are no statistics kept but many families participate in both organizations so the parents were most likely members before they married.
boy scouts
Boy Scouts were founded first.
A Patrol.
No, the Boy Scouts were founded in 1909. The Girl Scouts were founded three years later in 1912.
The Girl Scouts and Girl Guides share the same motto as the Boy Scouts. This motto from 1907 is 'Be Prepared."
As in Boy Scouts or Girl scouts? Yes but their activities differ from scouts in the US.
Boy Scouts and Girl Guides/Girl Scouts are run by various non-profit/non-governmental (NGO) organizations, depending on their location.
Yes
The organizational counterpart would be Scouts or Boy Scouts. Girl Guides and the World Association of Girl Guides and Girl Scouts are a female based organization.
The girls are the Girl Scouts.
It is either Girl Scout or Girl Guide or Guide. The international organization is the World Association of Girl Guides and Girl Scouts (WAGGGS).
In English there are no masculine or feminine forms. English uses gender specific nouns for male or female. Girl Guides and Girl Scouts are specific organizations designed for girls, based in the UK. Boy Scouts (Boy Scouts of America) and Boy's Brigade, based in the UK are equivalent scouting organizations for boys. These organizations have world wide memberships and there are are a number of similar organizations throughout the world. Note: Girl Guides, Girl Scouts, Boy Scouts, and Boy's Brigade are proper nouns and should be capitalized.