Others wouldn't dream of it. If you are fording streams or hiking at high altitude for the first time, take a stick for added stability. Ski poles are not only helpful for stability on an ascent, they also help take some of the strain off of your knees on the way down. The height of your stick is a matter of personal preference. Most fixed-length sticks are shoulder height or higher.
Adjustable poles offer the added versatility of telescoping down to a short length.
Some adjustable poles have a special camera mount on the top of the handle that turns your walking stick into a monopod for slow exposure photography. Make it fun for them. Let them bring a friend. Point out the wildlife, and have them find special plants or trees so they learn more about the natural world around them. Be sensitive to children's energy levels and need for frequent breaks.