Her owner is a bit put off by the head flipping as she is accustom to riding with contact and nearly caused the mare to rear/flip.
I'm riding her now, and I have to start out on a lose rein and work up to light contact. I can manage a rein with no loop and constant contact, but there's barely any weight on the reins. However, when I start asking for engagement from behind, she will push on the bit which causes her to flip her head repeatedly. Advancing her beyond the very basics is slow going at best.
I've tried riding her through, holding the reins till she "gives", ignoring the head flipping thing, but nothing works, she just escalates and will smack you in the nose or pop up. The only thing that settles her is giving her back loose contact.
I am not sure what occurred at training but any kind of restraint on her head/mouth causes her to panic and rear/back/flip head. The owners are understandably hesitant to send her away again for training, but now just feel that she needs to be sold or found a home as their daughter is scared of her and the possibility of her rearing. So I'm left trying to figure out how to make her sellable and happy so that someone who gets her will want her.
Any idea on lowering her defenses and stopping the head flipping?