B.A.
Children for years have been learning to ride bikes without having a special bike, other than training wheels to learn. My kids received razors(scooters) and learned to balance on those and then picked up a bike in a very short amount of time. At 2 1/2 even if she is the size of a 3 1/2 year old she may not yet have the cognitive skill needed to either peddle or do anything but push with her feet. She may even not want to do this yet. I have an almost 2 1/2 year old and all the interest is not there and even though the desire to scoot is there the skill is not there for the actual ride. Get an inexpensive bike with well put on training wheels and closely supervise as it is still possible to fall, can't imagine you'd leave a child that young very far away anyway.