I'll caveat this by mentioning that i've only been riding for a few months now, my girlfriend even less, and therefore lack a significant amount of experience these other guys have..however a different point of view.
The America was my first bike (ignoring the ones i rode on for my 5 day direct access) and i found it reasonably easy to ride as long as i took it fairly easy and stayed within my skill level. A few months later i'm significantly more confident and while still not able to throw it around with ease (i still suck at tight corners) i can see that by riding lots on it that i've got used to its different positioning and weight etc.
My girlfriend failed her test first time and spent 6 weeks on a Chinese bike called a Skygo. It was a 125. Once she passed her test after that 6 weeks she got straight on a Triumph Scrambler which i believe is roughly the same as a T100 but with a bit of varience in engine tuning (?) and style (Steve McQueen!). About a week later she's successfully translated most of the skills she picked up on the Skygo to the Scrambler and again with a bit of care and attention will no doubt be 100% comfortable on the thing soon enough.
so in terms of picking a bigger bike as your first (or in Tanyas case her almost first) i think it's totally feasable.
however to reiterate others points.
you will probably drop it, i've dropped mine once and so has Tanya (dropped hers that is) and it's a fairly gutting experience.
I realised beforehand i was likely to drop mine so had kind of prepared myself mentally for it anyway. Plus i'd bought engine bars (figuring it would be cheaper to repair if the engine was safe) and put 4mm carved/decorated vegetan on the exposed bits of tank and handles. The result, no scratches (but my heart in my throat).
Tanya was less lucky when she dropped hers and snapped the drivers footpeg off. Again replaceable but again totally gutting for her.
personally i think because of the way i am sat on the America that i'm less likely to drop it than Tanya on her scrambler (my lower seating position vs her higher one).
anyway, i guess i'm ultimately saying that from my point of view there's nothing wrong with getting the bike you really want (both me and her did - though she dropped the Skygo about 1037 times beforehand) it just needs treating with a bit of respect and the foreknowledge that you'll probably drop it at some point (which is deeply gutting, but liveable with if you prepare).
but both are awesome machines (i do occasionally steal hers for a hack around and a bit of wire fence jumping)
All the best,
Anthony
