My dd would like a bike and her scooter is on its last legs, so I’m finally giving in. However slightly confused as to the right size. I can see 12 inch, 14 inch, 18 inch wheel bikes with stabilisers on Argos, but it’s not clear what difference the wheel size makes. For a 5 year old about average/maybe slightly below average height for her age, which size would you go for?