The rigid one is a plus bike - it has >800g 2.6" tyres....
Swap them out for something smaller along with some lighter inner tubes and you would probably knock a good amount of weight off it....
Will see how much the one I have ordered actually weighs when it arrives
I have just ordered a 24" vitus for our youngest - https://www.lfgss.com/conversations/359943/#comment15816273