Not quite sure what play with her means?
This is a difficult situation, if i thought she was just trying to get you to leave her alone, by coming at you, I would say everytime she does it I would tie her and make her stand for an hour, right after a swift smack to the nose. But if her intent is to do you harm, I can not with a clear conscience recommend you keep working with her.
How long have you been working with her?
Has she been worked with prior to you purchasing her or is she off the pasture?
Not that it should matter but what is her breeding?
Our daily afternoon routine is to catch and tie (with their head up) for an hour, while their tied up the boys clean their pens, prep the feed and basically do things in close proximity to the calves so they get used to activity. After they have been tied, they get blown out, rinsed, blown dry and hair worked. Prior to getting turned out and fed the boys worked on seeting them up, calves do not get turned out until they cooperate, does not take long for them to find out the faster they cooperate the faster they get turned out.
The boy I'm helping out this year has a steer and a heifer, they steer is a beast to get caught but once he is caught is easy as pie to work with, the heifer is just the opposite, she walks up to you, lets you put the halter on and then fights you the rest of the way (she is getting better everyday but it is a slow process) She loves being groomed, scratched even rinsed just does not want to lead, In her case she is pigheaded, I am not sure if your heifer is mean or just figured out how to get you to leave her alone.
If she is truly mean and wants to hurt you, you may want to ship her for your own safety.