Yoga therapy varies depending upon the clinical condition, age group, the nature of the body of the patient with regard to flexibility and rigidity. General line of treatment is that all standing asanas like tadasana, trikonasana, kati-chakrasana, ekpada-hastana, garudasana, etc. (based on stamina - no forward bend) are very useful to contract, stretch and strengthen the spinal muscles and to relieve the back pain. However, the precaution is that one must not overstretch or understretch the muscles.
Thereafter, seated twisted asana like ardhamatsyendrasana and vakrasana and then back bending asana - bhujangasana, shalabhasana, etc.
Among mudras, you can do meru-mudra (thumbs up mudra). All spinal problems can be handled with this Mudra.
But adopting the yoga therapy, you need to go through the cause and diagnose your mother as to what sort of back pain she is suffering from.
Again warn to do only under supervision of qualified yoga therapist.
