My horses Hooves!?!?!?!?!?

My horse has a problem. Everytime i try to pick up my horses hoof, she does great i run my hand down her leg and she lifts her foot up but once im holding her leg she pulls away and she tries to fall or something so ill let go and people tell me that ur supposed to let it go so they know that theyll get their foot back. But if i hold it she starts to try and rear and fall or something. And im not that strong to be able to hold it from her anyways. Shes BIG so she very strong. Even he ferrier has trouble. HOW DO I TEACH HER NOT TO DO THIS!!!!