I always encourage little ones to get mobile as soon as they are able.
I teach them to hold onto the pram, my hand or one of the big kids. My oldest daughter loves helping and making the babies laugh! It's so wonderful to see little ones' confidence, steadiness and sense of humour develop as they learn how to negotiate pavements and watch the world as we go by. We have to take our time so I usually leave early to allow for walking time!
