UK Scouting is fully non-gendered for all ages; see Scouting for All and the Equal Opportunities Policy: http://scouts.org.uk/about-us/key-policies/equal-opportuniti....
UK Guiding allows girls and young women, but fully supports gender self-identification: https://www.girlguiding.org.uk/making-guiding-happen/policie....
Scouting and Guiding in the UK are refreshingly progressive organisations. Source: current Scout leader.