Read all you can. Dirt bike class is good but seat time is what really counts. A two day seminar is good and will get you in touch with basics. But practice is what counts.

If you do your research, following Ride reports here and over on ADV, you'll learn about the F650GS problems, which are many.

For my money, the F650GS is:
Over priced
Heavy
Expensive to fix at BMW dealer
In some cases requires proprietary dealer computers to work on
More frequent break downs than comparable Japanese bikes

Look at what Lois rides NOW, not what she rode when she was starting out as a raw beginner. That Serow she had was junk from the day she started. She should have never taken it. The book will make this very clear.

Lois NOW is riding another Yamaha. But a nicer, newer one. A TT250. One of the toughest little bikes out there and reasonably priced. I listed this bike in my initial list back a few posts. It's way way better than the Serow, is light and can be made fairly low. (lowering links)

The Serow is a mid 80's design, the TT250 came along in about 2005.

If you end up going two up, the Suzuki Vstrom (DL650) is the best bike in the world at the moment, all things considered, IMHO. The more you read and study, the more obvious this will become.

The Suzuki DRZ400 is a fantastic bike but not two up capable. Should be on your short list for the males in your group. Also consider XT600, KLR650, DR650. All good RTW bikes if set up properly.