Been out of Scouts for decades so I don't know what sort of resources they have for sale, but I know the many and various Girl Guide songbooks are loaded with songs which are either appropriate for your age group or could easily be adapted. In Canada at least, there are Guide shops which cater to just this kind of need. My wife has lots for her Brownie group, and I have great contacts within the organization at the national and provincial levels.

Feel free to contact me by PM and I will be happy to send you some samples.

In the meantime I will look up some titles for you.

Peace, Mooh.