Girls or boys, women or men, shouldn't be any differences in what you start them out on.
I get approached fairly regularly by people that say: I used to ride, I had a (insert any make model), I'm thinking about getting back into it, BUT I'm concerned about all the distracted drivers (idiots in basic terms). I smile and tell them NOT to get back into it, that with that fear they will surely become the victim they fear.
Motorcycling is about risk management and self confidence, that the throttle is as much your friend as your brakes. Before I ride with someone new I ride behind them and watch their moves. Go smooth first, fast second.
One of the good aspects, and there aren't many, about living in Massachusetts is that they offer a rider safety course that, if you pass, leads to a motorcycle license on the day you complete the course; last time I checked it cost about $250. If they won't pony up the conversation shifts to something else.
For the confident ones, I encourage them to purchase a 2 or 3 year old 250 four stroke twin, any make (same as used in the rider safety course). Tell them I will teach them how to maintain it and that if they don't like it they can sell the bike for very near, maybe more, than they paid for it. Same if they want to upgrade.