Thigh pains are usually due to tightness and weakness at the same time Ask her to not sit for more than 20 mins needs to stretch out her legs if she sits longer A few exercises can help her keep the muscle relaxed and pain free I can send you the exercise pictures on online consultation

Contrast Fomentation (Hot and Cold). Quadriceps strengthening exercises- Quad Clenches: Lie flat on your back or sit upright on a chair with leg kept horizontally on another surface. Now, tighten the muscle on the front of the thigh by pushing your knee down. You should feel your thigh muscles clench, Hold for 3 secs. Repeat 10 times twice a day. Short Arcs: Lie flat on your back or sit upright with your leg placed horizontally on a flat surface like a chair or bed. Place a rolled up towel under the knee. Pull your toes towards you and clench you thigh muscles. Slowly lift your foot up off the bed until your knee is straight (keep your knee resting on the towel). Hold for 3 secs and slowly lower them on the chair. Repeat 10 times twice a day.

Please specify which side of thigh is more painful, front, back, or either sides, so can help accordingly. visit a nearest physiotherapist who will assess the exact cause behind the pain and will treat accordingly.

Do strengthening exercises and streching exercises

Meet physiotherapists and proper diagnosis and treatment