Seems that H-D-3 is new for 2014? My perspective mind you. She becomes confident about riding. She now wants to try 2-wheels. A rear wheel off ebay, they never messed with the rear frame, meaning, took one off the assembly line and retro'd off the swing arm and rear frame. However, if this is a special 3-wheel frame, oh well? Trade-in, loose your shirt time.
One more perspective. When I teach a new rider, I sit on the back. I said to her, I'm going to kick your hands off the bars, I have no time to tap you on the back and say let me take over. Sure enough, a car turns left in front of us. I swoop under her arms, grab the front brake, clutch, the whole nine yards. We missed that idiot.
So say my guess is you let her ride alone and she could not balance the start up and stop, ha-ha was it? Where if you were on the back, countersteered the body english, you let the clutch out and let her practice steering first. I forgo the clutch to throttle. I more let her lift and cruise so she gets used to the power delivery. Might be the wrong way to start out, but I see a lot of input to ride a bike. I mean, once you figure it all out. The 6 or so hand/foot/brain inputs is it?
The gradual would be?
1. The ride - No shifting needed. No brake work. This is on the road, no traffic, just ride and keep an eye way up ahead for lefty/driveway pull out/holes or debris coming = 'The Brain' trust. Trust your instincts.
2-3. Braking - That means both at the same time. You can get conditioned to keep using one brake. So the discipline is to use both with the emphasis on the front having more stopping power.
4. Steering - Without thinking, the bike is going to steer you push/pull to find out.
5. Clutch - Once the others above feel comfortable, time to practice from a dead stop.
6. Throttle - The timing of both to feed one another. The feed is this side of linear. In other words, you feed enough [clutch] so as not to stall the engine, but to [throttle] up the engine as you feed at a slow rising rate.
If she wants to take another crack at it with your input on the back, she might take the 14 out and you're stick with the ??? you bought.
Tormenting the motorcycling community one post at a time