Hi, I'd like to help you with your question.
It sounds like your daughter may have a personality that leans towards being fearful. Some children are bold, some are studious, and others are shy. Your daughter happens to be fearful.
There are ways to address this. The best option is to take her for an evaluation with a mental health therapist. They can determine if there is an origin for your daughter's fears and what can be done for her to help her. She may need short term therapy to help her learn how to face her fears. To find a therapist, talk with her doctor for a referral. You can also search on line at http://therapists.psychologytoday.com/rms/ in the US or http://www.bacp.co.uk/ in the UK.
You can also help her at home. Learn what you can about fears and phobias. This will help you know how to respond to her when she is afraid. Here are some resources to help you:
What to Do When You Worry Too Much: A Kid's Guide to Overcoming Anxiety (What to Do Guides for Kids) by Dawn Huebner and Bonnie Matthews - for your daughter to read
Freeing Your Child from Anxiety: Powerful, Practical Solutions to Overcome Your Child's Fears, Worries, and Phobias by Tamar Ellsas Chansky
You can find these books on Amazon.com or your local library may have them for you.
I hope this helps,