Issue with her hip/thigh/leg stiffness.

Hello. I am writing this for my wife. She is now 31 years old. She has certain issues as mentioned below: 1. Her left leg starting from back hip to knee to back thigh is getting stiff after she sits for a long time. The same issue is happening for her many times while walking. 2. Her left leg side is getting stiff and stuck some time while getting up after sitting for a while and sleeping (if the left side is covered while sleeping) as well. 3. The back pain is also severe many times in a random manner. These all are observed post her delivery. She started having calcium tablets based on the Doctor's advice for a period of time. It was reduced. Then, again it's been started since last 5/6 months. She is not on any medication only except Homoeopathic medicine for piles. Please suggest.