The Society of Shoe Fitters and Children's Foot Health Register members believe prevention is better than a cure.
Ill-fitting shoes are the one item of clothing that can seriously damage your health long term. Like eyesight, hearing and teeth, feet need careful monitoring over the next 16 years and require expert advice. A baby's foot is mostly sift cartilage. Just like a bonsai tree, they ca become misshapen if you restrict their growth. Putting a small child into baby-grows, socks/tights or shoes that are too tight, can do untold damage that may not become noticeable until they are older. It is important to let a child walk unaided across a room before putting them into shoes - nothing wrong with bare feet indoors until then.
A good quality, supportive pair may seem expensive as they will be outgrown before being worn out (an infant should be fit checked every 4-6 weeks and they will have growth spurts as they get older), but well-fitted quality shoes are an insurance policy for their future development and mobility. Comfortable shoes allow you to walk naturally. No-one likes backache or neck ache, or looks forward to a knee or hip operation.
Once children buy their own footwear it is difficult to avoid extreme fashions that are unhealthy like high heels, pointed shoes, cheap ballerina pumps etc. Talking about their feet when they are younger (and perhaps showing them how awful feet can look and how it can affect other parts of their bodies) will help educate them when shoe shopping for themselves.
A professional shoe fitter will assess how a child is walking, what shape their feet are and if they can see a potential problem presenting itself i.e. toeing', pronation, supination, etc. Using a gauge is merely a guide - just a starting point. No two pairs of feet and no two pairs of shoes are the same and gauges are calibrated differently too.
Feet are sensitive, hard-working parts of the body. Please look after them professionally. There is no charge for the expertise of a qualified shoe fitter and all children deserve a knowledgeable person to assess their feet and understand which pair of shoes fit correctly.