Don't push her towards a 'more beginner-suitable reptile'.
This is the biggest mistake that parents make when a child wants a reptile, and it goes equally if not more so for your gf.
typical scenario:
1) 'I want x'
2) 'well x is deemed harder than y, so that's what you get instead'
3) 'y is cool, but now I've had it for six weeks, it's still not what I wanted and I'm bored'
4) animal suffers neglect or is given to a new home
My girlfriend's first reptile was a panther chameleon which she purchased last february. He's healthy and amazing.
The one thing that makes certain reptiles TOO difficult for 'beginners' is the ones we don't know good husbandry techniques for. I would say that Kinghorni scrub pythons and Boelens pythons are probably not a good idea for a beginner.
Many chameleons, turtles, and torts however are successfully kept with well-published husbandry techniques in thousands of homes. Talk to people who have kept whatever species she decides on, and emulate their husbandry techniques and modify as necessary to fit your lifestyle. If she's settled on a chameleon, I believe my gf read through one of the popular chameleon forums quite a bit (I forget which one however). I highly suggest finding an active species-specific forum.
I WILL say that keeping chameleons isn't cheap, relative to snakes at least. A wide variety of different types of live feeders, a good misting system (makes a huge difference, trust me), and the initial cost of the animal and caging/setup are all pretty high. That said, I love our panther chameleon and he's more than worth it.