No it's not normal for anyone to have a rectal prolapse. It means that you are either straining significantly during a bowel movement, or there potentially could be some thing making it prolapse such as a polyp however in any case you should be evaluated by a pediatric gastroenterologist or a pediatric surgeon

It's not normal but it does happen, typically if you are constipated and have a lot of straining while stooling. Make sure to drink plenty of water and eat high fiber foods to help prevent further complications.