How dangerous is a child or an adult to get x-rays often? How long must a person wait to get more xrays? My grandson plays football he is in a team, plays every sunday, sometimes he gets hurt, but his mother says that x rays are dangerous when taken too o

Not so much. The technical improvements in x-ray machines now allow us to get clear and reliable films at a fraction of the dose used decades ago. Some forms of x-ray, like fluoroscopy are higher in their dosing than simple films. That said, limiting their use to those situations where an exam does not provide the needed information is very important.
All. All medical professionals are keenly aware of the potential risks posed by exposure to x-rays and weigh these against the potential benefits based on their clinical judgement. When requested, x-rays are obtained to answer a clinical question. In this case, is there a fracture, dislocation or other abnormality that can be seen on plain radiograph? In your grandson's case, if he gets hurt, the physician evaluates the injury by physical examination, and then decides if he/she can make a confident diagnosis. Since you cannot see through the skin, the x-ray provides a way to see the bones and joints and provide a more confident diagnosis. You have to weigh the risk of missing something that is important -- like a fracture or dislocation -- against the risk of radiation exposure. So the x-ray improves confidence in diagnosis and therefore guides them to a more precise treatment. Radiologists and technicians are trained to ensure the exposure is minimized, to limit any potential risks. That being said, the overall risk of a single x-ray exposure done properly is extremely low. You can get more exposure to radiation flying in an airplane.
All. All x-rays involve the use of radiation which can be harmful if performed too frequently. Plain x-rays use far less radiation than ct scans but one should avoid getting any x-ray unless there is a need to do so. And, if there is a need, x-rays and other radiological procedures can be critical to making a correct diagnosis and guiding treatment. As a matter of comparison, one typical chest x-ray will deliver about the same amount of radiation that the body will absorb from cosmic radiation after 1000 hours of flying in a commercial airplane.