Park ranger is a very small class;she should try for a real enviromental job like working in a sweage treatment plant or one of many enviromental jobs in industry meeting EPA regulations.
Only a few people are need to show children where Mr. Squirrell lives.....
Setting up aquaculture, rehabilitating brown-field sites, teaching gardening to urban youths, setting up and running urban and suburban food-coops, starting and running urban food gardens for food banks - there are options that fit both her degree and her desires.