3 plain film x-rays is not a huge deal. A child having a CT, angiogram or nuclear med scan would get a greater radiation dose in a single scan. Or a child who has been in an accident or being investigated for non accidental injury could have a lot more than that at one time, they often have to have a whole skeletal survey.
Obviously as few as possible is ideal but the few they are having wouldn't generally be of a concern. A coin stuck however could cause serious issues and may require surgery.

Hope your friends babe is ok.