My daughters left calf is swollen. and heavy to lift why?

Other symptoms like: redness, localized heat, tenderness, pain, limping or inability to bear weight help determine if the swelling is due to tumor, trauma or infection. Take her to her pediatrician for evaluation.

Possible injury: You mention something about a "fractured knee". I am concerned about this in association with a swollen calf. There may be a problem with blood return, a possible blood clot, or an injury to the leg itself which is causing the swelling. In any event, further evaluation and x-rays are indicated. May even need an ultrasound of blood flow. But asymmetric swelling of a limb in a child is NEVER normal