confidence boost.

Anyone knows any tips or things to do to boost self confidence of a 4 year old girl? She is super shy from everything. Always scared of everything. Freightened from the smallest things. Jumping of her seat when hearing any loud noise. If another kid would yell at her or try to snatch something from her hand she would just let go & get scared of them. It's heart breaking to see her like that!! It's way too tough outside for a personality like that.