Great thread! But may I make a statement?
We seem to focus on 'the beat' as if there is only one? Turkish and Arabic music is infused with many beats at diffeent tempos. For the Western ear and new dancer it is difficult to hear all of them and know they are all part of the music. Also too, the drum may be the foundation, but sometimes it will weave in and out of the song.
So Jane which 'beat' are you trying to ge her to hear? Or are you talking about a specific rhythmic pattern?
Can she tell the difference between drums and other instruments?
I have many students who are challenged in terms of music and moving at the same time. Patience and acceptance are the true teachers in this instance. I can't imagine another dance form that would be more forgiving than belly dance...so I'm glad to hear that she's sticking with it(and you too!

)
Yasmine