A Self- Esteem Checklist. I don't relieve believe in the terminology "self-esteem", for me, it's more like "self-worth", but this list can be helpful to get a better understanding of an individual's view of themselves.
Self-Esteem booster group activity: Have one girl sit on a chair in front of a white board while the others write positive phrases about them. They cannot peek at what is being written. Take a picture and give it to them.