What to Do When You Worry Too Much: A Kid's Guide to Overcoming
Anxiety (What-to-Do Guides for Kids Series) by Dawn Huebner
https://www.amazon.com/What-When-Worry-Much-What/dp/1591473144/Just a note about the above book: It contains a lot of references to
TV etc and that can be modified as you go depending on how well the
child reads (how much she'll notice you changing the wording) and the
sensitivities of the family.
Freeing Your Child from Anxiety, Revised and Updated Edition:
Practical Strategies to Overcome Fears, Worries, and Phobias and Be
Prepared for Life--from Toddlers to Teens by Tamar Chansky Ph.D.
https://www.amazon.com/dp/0804139806Breaking Free of Child Anxiety and OCD: A Scientifically Proven
Program for Parents br Eli Leibowtz Ph.D.
https://www.amazon.com/dp/0190883529