My sister has broken elbow. Should I be worried about it?

Broken elbow. The treatment depends on where the fracture is and how displaced the fragments are. It can treated in a cast or it might need surgery. This can be discussed with your surgeon.
Depends. Some fracures are relatively simple and can be treated with a few weeks of cast immobilization other fractures with displacement or growth plate involvement may require intenal fixation with pins or screws to obtain the best results.