In my experience,these are bad/counterproductive things to do on a rearer:
Tie downs/headcheks/standing martingales
Again in my experience, I have had success with these ideas:
Forward, at all costs. I growl, I flap my arms, I kick, over under the reins, yell. Basically making the horse think that the sky is falling in if they don't go forward.
Disengaging the hindquarters. This is what is happening when you say she doesn't rear when you turn her head. Get her circling, then try moving forward. If she gets stuck again? More circles.
The MAIN reason for a rear is a broken forward button. A rear can physically only happen when forward momentum stops. This is why backing up can be a bad idea, the weight is on the hind, just poised to go up. Go over forward from the ground up. She should ALWAYS listen to your forward cue, if not, escalate the pressure.