12-16-20-24″ is a steady progression. 14″ is a waste unless you buy into Isla’s perfect size for every ‘ickle one. Tyre choice is dreadful for anything less than 24″.
15.5″, makes the playground come alive.
Was the funniest thing I’ve read in ages.
Unless you have other siblings, buy used. My bikes were all passed down. And most mainstream brands are just fine these days. TiredTeens cut their Gnaar on a rigid steel 16″ Raleigh Kobo with alloy V brakes and adjustable levers. It wasn’t the lightest, it certainly predated Queen Isla’s assault on the children’s bike market middle class angst, but it was fine for five mile rides in the country with Bridleway action. They could both ride without stabilizers by the time they graduated to it, because I didn’t like balance bikes and taught them on 12″ wheels.