When I was working with a trainer putting first rides and saddling on a horse, She always lunged the horse with all the tack on first, and then when I would get on, she would still have the lunge line, and would help encourage the horse to go forward when I put my leg on, said walk or trot or whatever, and kissed, and that always helped the babies learn to go forward without scaring them, and without letting her think that just standing there is fine. And trust me, I am working a quarter horse gelding, halter horse, who is very green and lacks confidence, and just getting his feet to move, while yes it helped, he still thinks a few months down the road that when asked to trot out, or canter, that doing pirouettes, and tiny little circles, is much easier. Still haven't quite figured that one out yet lol. But on him you can't push him. Simply sitting on his back, and bumping him with your leg and trying to out wait him doesn't work. He personally is just a stubborn horse, who has some other problems, but if pushed enough, or I try to out wait him long enough, he eventually either rears straight up, slams himself sideways into the railing, or tries to back up up a hill. So if you are going to try the sit and wait her out till she moves, be careful that she won't end up getting so upset or confused, that she goes up, or does something else to try and get rid of the frustration.