Most children can start riding a tricycle around 2.5 or 3 years. When your child can stand and walk with confidence and understands cause and effect (like knowing that if she runs into the wall, she may get a bump on the head) then you may want to get her a trike. To work up to this stage, you may want to start with a three- or four-wheeled push bike. Then she can learn that if she wants to move, she will have to push with her feet and legs. Then move up to a trike so she can build her muscles and learn some balance.