Jay,
I appreciate your advice very much. I will relay this information to her. I did emphasize to her many times and still do, that the key here is
to do it comfortably, gently, with zero strain or stiffness and that if the retention is comfortable just for a second, than that is ok. I also explained, she should first relax her body completely, before she starts with pranayama. Interestingly, she enjoys it the most if she is practicing while lying in bed and the evening session helps with her sleep (she had problems with sleeping). We started just with deep breathing, which she found pleasant and i ve learned that it is best if she sticks with it. I didn t realize that this was a form of pranayama by itself.
Thank you friend!