World Turned Upside Down
Read Aadil's reply:
The first thing you can do is to give her more time. Let her become extremely comfortable in the preparations. Most teachers are in a rush to get their students to accomplish things because it boosts the ego of both the student and the teacher.
A few months down the line, when you believe that she is ready, use the teacher-training you have received to help her up in the pose while supporting her body fully. In this way, your student will have no fear because, even if she suddenly collapses her elbows, she will not fall since you are holding her up. Most Iyengar and Purna Yoga teacher-trainings will teach you how to do this.
After your student has built up her confidence, teach her how to do these poses against the wall while you hold her. At the next stage, ask her to go up against the wall by herself. The next stage is when she does the poses a foot away from the wall, with the wall behind her functioning as a psychological support. The final stage will be doing the poses in the middle of the room.
Please remember during this progressive process that it is only when the student is ready that you are to move her to the next stage. The readiness must be in her body, her mind, and her emotions.