Leg swelling for long time. Guide.

Hello all, My mother had ankle swelling issue for long time, when traveling, or if the house chores are high, she used to get leg swelling in the ankle, but it will reduce automatically in few hours or next day. We checked it , the doctor said it is because of the water stagnation. It was manageble. In 2020 Feb, she fell down and undergone a knee surgery for fracture, plates are kept. Though she has recovered, the leg swelling is severe now. Full leg is swollen now where the surgery is done. Left leg is where the surgery is done. Attaching a photo. Leg swelling is there in both the legs. Major swelling is there in the left leg. We did some blood and urine test for kidney related. Everything is normal. What's next , can someone guide.