Personally, I'd just have her jump right into it. Find a simple song she knows, and start with that. Move on to the next song, and she can learn what she needs along the way.
Usually a person wanting to learn wants to play!, so hold off on the theory unless she's asking for it, or hits a point where she needs to know it.
I am not an instructor by the way.
...so ever since then, I always hang on to the buckle.
