A 10-year-old with a fractured ankle... Why isn't it healing? 😢

I fell during school class and fractured my ankle boneㅠㅠ So now, I've been in a half cast for five weeks, getting weekly X-rays and physical therapy to monitor the progress.

At first, since the child was young, I was told that about 4 weeks would be enough to recover, but even today, after 5 weeks, the recovery is not satisfactory, and the cast has been extended again. It's been almost 6 weeks since they started using crutches... both the child and the adults are going crazy. They say that at 10 years old, bones heal really quickly, so why is our child's recovery so slow? ㅠㅠ I'm so upset, sad, and heartbroken...