Originally Posted by
tjspiel
The advantage of the 3rd wheel contraptions is the additional mobility and that the kid can help

On her bike with training wheels she can only go so far and riding up any kind of incline means you've got to push her. Don't get me wrong, if it's a 4 block trip to the park, she rides her own bike.
You can also take a break from pedaling and let her push you along.