How many miles does it have on it 

1615 miles

Well did you get the nut loose on your clutch if not I would change the transmission oil and adjust your clutch cable at the handlebar and go for a ride you might be ok that’s not a ton of miles on it

Not yet. Sprayed some penetrating oil on it today. Going to let it sit overnight and give it another try tomorrow. If no luck, I’m just going to let it be and stick with the adjustment on the handle for now. Transmission oil has been changed. Took off the carb again and gave the pilot jet another cleaning for good measure. That sucker has one small hole. Hoping to reinstall and give things another try in the next few days.

**UPDATE**
My daughter took it for a spin last night for the first time. She road it around a nursing home which is not currently open, so it's a safe place to practice. The first couple times around she was able to shift it to the upper gears and the biked sounded great. She wasn't going very fast, so not sure how I high of gear she made it to. She wasn't sure either  .

Then the shifting was not as smooth. When she'd shift and roll on the throttle, the engine revved but the acceleration didn't match. The bike didn't sound good. The speedometer also seemed to stop functioning. Based on our limited research, we're suspecting the clutch is slipping but it could also be a lack of riding experience. I was never able to make the second clutch adjustment (couldn't loosen the lock nut). We know some experienced riders. We thought about asking them to give it a ride and get their opinion.

thoughts?

You might have to remove the left side cover to get at the actuator so you can loosen the nut and get the clutch adjusted.

The "internal" adjustment is critical. You can't make up for a too tight internal adjustment (causes slipping) with the cable adjustment at the handlebar.

Video is always nice. Post to YouTube and link here.

Yeah, you've got to get that adjustment nut loose to make sure it's set correctly. May need new friction plates as well, but try the adjustment first. For a new rider, it's possible she was holding in the clutch lever a bit. Sometimes you don't realize it, but you're pulling in slightly, and that's all it takes to cause slipping.

If you changed the transmission oil, hopefully you used the type for wet clutches. If not, this will cause slippage.

Might end up having to go 'in' if adjustments have clearance.
Be sure she isn't holding the clutch with tension on the lever while riding.

MarkT…is this the left front cover you are referring to?

drive.google.com/file/d/1FSTDNfKj75JtQJI...Qa/view?usp=drivesdk