I was just re-reading this thread.....
First - make sure the bike FITS her - even if that means lowering, changing the bars (including wiring), hands fit the brake and clutch lever (there are things that can be done for small hands that doesn't affect performance).
I changed the bars on my America w/in a month of purchase. I did the same on the Road King, and lowered it before I even picked it up!
Second - let her, make her practice. Parking lots and riding the same road LOTS. I have a couple roads with curves and hills that I ride over and over for practice - still to this day. She's going to want to keep up with you, but really, really encourage the "ride your own ride" theory and don't push her to go faster or farther than she is willing.
(I relearned that at the SWTF this year - I can't keep up with Dwight and BigBill and shouldn't even try - its outside my comfort zone - but that is OK!)
The other thing I notice here - all you guys say get her something small to start on -
how many of you did that and how many of you went out and bought your first bike as big as possible or the America is your first bike? (except those that started as kids)? This triumph does have lots of power, but she's going to be very bored very quickly riding only on the side streets on a little 250. I wouldn't get on a major road on such a little bike -I want the power to MOVE when necessary. Why is it different cause she's a girl!?!? Let her chose her first bike!
Anyway, off my soapbox

Becky