Yes, I agree and the MSF course is mandatory in Florida to get a MC endorsement, once you pass the class you just take the paperwork to the DMV and get a "Motorcycle Also" endorsement on your DL. She just wants some idea of how a bike works before she goes in front of 15 or 20 other people in a class. BTW, if you don't have the endorsement and get pulled over or stopped at a check point, they take your bike on the spot and start writing tickets, cost almost as much as a used bike to fix all of that mess with fines, towing and storage. The class alone is almost $300.00.
Shame it costs that much. In some states where it's mandatory, the state pays for it. Some states use revenue generated from motorcycle citations and sales tax on motorcycles and uses it to fund the MSF course for anyone who wants it. A lot of times, when the helmet law is repealed, the 'trade off' is the MSF course being mandatory or provided by the state, since the MSF course is a proven successful tool in reducing or eliminating motorcycle accidents.
If she wants to get familiar beforehand, two things;
1) She doesn't need to. Lots of people will be getting on a bike for the very first time there. When my wife took her class, she was one of only two people who actually owned a bike. Others were 'planning on it', or were using the class as a way to see if they'd like it, or just as something to do, or even just planned on riding on the back of a bike but thought it would be good to know how it works before being a passenger!
2) Just take it slow. No need to be in a hurry. Maybe find her a nice, wide open parking lot. One thing that is hard for some folks to understand, but we take for granted, is the bike gets stable with speed. Brand new riders are sometimes afraid to get moving, but then the bike is unstable. (Same with kids learning to ride a bicycle. It's easy, but you have to work up to the speed the bike requires to stay stable). Encourage her to try getting up to speed, feet on pegs, in a straight line first. Don't worry about shifting just yet. Just work her up to getting her feet up on the pegs in a straight line, until she's comfortable moving the bike forward with enough speed to keep it stable.
Baby steps, baby steps. Some people can hop on and go, but your fiancee sounds like my wife; one that is going to have to do it in steps.