My wife decided to give riding bikes a go a couple for years ago after I took it up again. She learnt to ride down some back lanes on an old GS500 (really a rat bike), as a lead up to doing the Direct Access. They taught her on CB500 twins, solid and stable. She wanted a 620 Monster but we couldn't afford it that year and she ended up with a 600 Bandit. A mistake in hindsight, because it was too high (she is "not tall") and too top heavy. She pranged that the following summer under some odd circumstances (long story), and then got the 620 Monster she always wanted. Her leg was in plaster for 4 weeks having broken it in the accident, and then it was take delivery of the monster, get to the 600 mile service in about 2 weeks and then 3 days later she got used to the bike by riding it 2500 miles around France as we had a Gite booked in the Dordogne. She loves that bike, and in fact just took it out this afternoon for her first ride of the year ... 5 months or so off it and got straight back into enjoying it again. Says it all I think.
As regards restricting a monster ... when we were first looking for bikes for her I asked about the 400 monster that they sell in Japan. Apparently it is so underpowered it is not worth considering, because the Monster is not a light bike. HAving said it's not light, it does have a low centre of gravity so it doesn't give her the trouble that the Bandit did and she can manhandle it. That is mainly practice rather than strength, or perhaps a combination of both. Don't be put off by one bike being a few kg heavier, the monster doesn't feel it.
All in all, I don't think the direct access system did her any harm, as she hurt herself on the Bandit "stopping" from about 50 mph not going too fast! It was down to exerience and "survival reactions" which go against what is safest on the bike, rather than not being ready for a 600.
Hope that helps, and you didn't fall asleep TOO early on ...
Henry