Niagara is genuinely great with kids — but the day is long and the sensory load is high. Plan around the boat, not the other way around.
Hornblower (or the Whirlpool Jet) is the highlight every single child remembers. Book the earliest sailing your tour offers; kids are fresher and the queue is shorter.
Clifton Hill is a tourist trap and your kids will love it. Build in 45 minutes after lunch for a quick ride or arcade — it buys you patience for the afternoon viewpoints.
Skip the wineries. Bring snacks: tour-guide veterans always carry granola bars, because the gap between the boat and lunch can be brutal for a hungry seven-year-old.
Winter tours with kids work better than you'd think — illuminations after sunset, no boat queue, and the falls partially frozen looks like another planet.