Girl Scout Fiction Books 1960-Current
This story hit home for me,
I had to wait until I was 7 years old to join also!
Other than Elizabeth Beatty is the pen-name for Teresa Holloway and the book was considered adult reading, I couldn't find much to show about Girl In Green.
Surprise! Dorian Finds The Brownies
was part of the 1968 Cracker Jack Miniature Book Series, #9.
Two versions of the cover.
There's a sequel to "Leave it to Lexie", called Happy Birthday Lexie. I don't know if it has any Girl Scout reference.
Troop 13 survives 2 mysteries!