Adult stabilizer wheels ,16" wheels mount securely to bike frame **The wheels work great as long as you are going in straight line , problem is turning . very difficult , i have both wheels about 1.5" above ground.Turning requires a great shift of how you are sitting  and lots of leaning , not good for people with balance issues . the rider is 16 and about 130 lbs. any ideas it seems watching video of the product that turning is no problem .   **
In my experience, training wheels are an old way of learning to ride a bike and end up teaching the user to ride poorly.  As you've already noticed, turning with training wheels does not replicate how we turn when on two wheels.

The modern solution is to use a balance bike for the rider to gain a better intuitive feel for the mechanics of balancing.  These are essentially bikes without pedals, and a slightly lower saddle.  They allow the user to "stride" along and take very long "steps" while gliding between steps, hence an alternative name "strider"

You can engineer one from a regular 2-wheel bike by removing the training wheels, and removing the pedals from the crank arms.  Store the pedals for later refitting when confidence improves.  Its possible to remove the cranks and the whole BB axle, but that gets messier.

Similar results come from riding a scooter, but this tends to cause a favourite leg which doesn't translate to cycling as well.

If your rider is such that balancing may not ever happen, then a tricycle is a better solution.  At least the bike won't be able to flop ~5 degrees and then loose all drive from the rear wheel.   Two rear-drive wheels that always touch the ground are superior to a single drive wheel with two outriggers.