I have just finished reading Jonathan McKee's book, The Teen's Guide to Social Media and Mobile Devices: 21 Tips to Wise Posting in an Insecure World. You can take a sneak peak here. The book is easy to read, up-to-date (published in 2017), full of interesting information and real life stories. Jonathan gave some Bible verses and looked at the topic from a Christian world view, but the principles are relevant for all teens. There are discussion questions at the end of each short chapter so I think it would work well as a small group study too. I highly recommend it!
Short and sweet inspirations for Christian teen girls.