It takes a while to get a horse over being head shy. A lady's horse I worked on was 14 and you couldn't touch her head at all. I had to start at her shoulder, and stand next to her, work my hand up slowly, as I pet her - kinda like oops! I'm a little higher.... when my hand was on her ears, she tossed her head and threw a fit, and I held there until she quit. Then I moved away. that went on for about 3 months. She's totally over it, and with time, she's now allowing just about anyone to handle her ears, cradle her muzzle, etc. Just take your time.
Ask Often, Demand Nothing, and Reward Generously.