Sounds like you had fun, that's good, always have fun with the little ones!
A large cone (h:~50-60cm) is a very good in teaching skating. Also if your rink has these smaller goals, you could turn that facing down and it can be pushed like a "Zamboni" on ice, maybe collect tennis balls or similar with it. When I teach these 4-8 year old's to skate I had always a bucket full of tennis balls and I just throw these all over the ice and told the kids to collect them from between their legs by bending angles and knees to get low and by still keeping their heads up. When the bucket was full, I usually throw those tennis balls again, it was fun practice 😉. I get those tennis balls for free from local tennis club, they had thousands of used tennis balls lying arounf there…
These kind of skating "support" devices (~walkers?) are common around rinks here:
but I think that large cone will do the same. Maybe a some sort of steel chairs are also used.