I picked up a freebie sup a few months ago from a guy I bought a paddle from after talking about how my kids are getting into the water/surf/wind scene. I cut down my alum paddle (both blade & shaft) to kids size & we've been hitting the lake & harbour every week. Friday night I got home from work & asked, "who wants to go to the beach for some small waves". 10mins later we were on the water & I was watching my son doing the 'backwards walk' & falling off on nearly every wave...he did manage a couple of small runners & also caught a few on his knees.
Although we haven't spent much time in waves, my 8yo was proud as hell on Saturday paddling down the (glassy) Glenelg River with his dad whilst mum & his 2 sisters sat on a jetty fishing! The feeling was shared!

(BTW - my 6yo daughter ended up catching the only 'keeper' for the day - 37cm bream, angled it in all on her own - awesome day!!!)