The person I fear most while cyclin my 4yo on the back of my bike, is the insane bitch on a MASSIVE "Ebike", child on back, no helmets, speeding along the path, once knocking my 6yo from her scooter on to the road. Those of us without engines as just targets Sometimes.
This is a problem in The Netherlands too. The lanes are designed for speeds no greater than 20-25kmh but e-bikes can go significantly faster.
Ironically, I get worried when I see helmets, because those bikers often seem to ride faster than others, all things being equal...