Our youngest is getting big, so it's time for us to pass along our beloved yellow steer-from-the-rear tandem. I love it because it's easy to talk - much easier than if they're behind you - and they're in *front* and get to see better. It handles great, I love riding it. It's the right size for a smaller kid - both our kids started in preschool and grew out of it in 4th grade. We've had it 9 years and it's in good condition: I've replaced the drive train, bottom bracket, and rear wheel, it has nice cork handlebar grips, and a custom seatpost extension for taller adult riders (but would accommodate a wide range of adult sizes). Made in Grand Junction, CO, goes for $1400 new.
https://browncycles.com/bc/kidz-tandem/
The photos show a front generator hub and a windscreen that I'm planning to keep (but might be talked out of). Drop me a line if you want to try it with your kid!