Thanks for all the responses on getting my heifer's new behavior of pushing against me with her head under control. My vet said to punch her in the nose, this worked only minimally. The vet assistant said to have a tack in my hand. I was about to do this when I thought... this gal is halter broke. I hadn't put her halter on her as we weren't walking her across the street to the pasture. I put the halter on her and backed her up against the wall to reinforce who was boss. I held that halter up high to keep control of her head and all seems to work. I know I need to be real fussy as I don't want her to develop any idea that she has any control when the halter is on, so I'm working hard to maintain this. Maybe this will help someone else down the line when they encounter this.