Hello sir, from your history it is clear tht your mother is suffering from osteoporosis arthritis knee, she must be in early stages following things to be considered first avoid sitting cross legged on the floor and avoid squatting n avoid using indian toilets. She should start quadracips strengthening exercises n do lot of stretching exercises, use ice packs when ever she gets pain. If she still continues to have pain then consult an orthopaedic surgeon