As "First Bike"
Little background before my opinion. I am 57 years young have been riding since I was 13. Raced Desert and Motocross for 25 years. I am not in the greatest shape, drink too much beer, and ride my 990 like I stole it. Have only had the 990 for going on 5 months and still have my XR dual sport THIS IS MY SINGLE TRACK BIKE. I ride two up on the adventure alot (with a pillion as experienced as I am) lots of nasty two track and the Sierra NV bolder piles.
I will say I would not let someone I love with no experience ride my 990. It would be a bad experience for both of us.
The bike is difficult just to turn around in a parking lot for the inexperienced rider. IMHO you would learn the skills needed much quicker on a smaller bike.
That said some people are naturals, I have seen kids win their first race entered and never look back. This is a call your going to need to make.