I see you already have an answer, and I completely agree with BlackThorn, but let me add something as a fellow Israeli. Your GF is 17, that means 11th grade? In two years she will be in the army. Free. Making her own choices, financially and otherwise. What she does with her military service is her choice - her parents can't affect what she writes in her Manilla, nor what she says on interviews. That part of her life would not, cannot, include them. There's no threat her parents would able to hold over her head anymore - the army would pay her, feed her, clothe her. If she doesn't wish to live with her parents during military service, that can be done - through the Mashakit Tash. (I don't think situation coming to that would make anyone happy, but it's important to know the option exists. It's liberating to have choices.)

The army is a very empowering experience. Being an adult, being treated as an adult, doing something that's real and important and your responsibility - it's big.

I used to have a relationship with my parents not too different from what you describe your GF has with hers: my parents too had a very clear idea of what I should do with my life, paid only for what they thought I should have, reminded me of the fact that they're paying, and I'm not bringing anything into the household. It's a cultural thing. As a soldier, I was able to say "I'm an adult, I make my own choices. I'd rather you accept my choices, but I won't change my decisions if you don't. You do not decide things for me anymore." Military service changed both how I saw myself, and how my parents saw me. Even how my grandparents saw me. There wasn't even an argument - I've changed the dynamics, and that was it.

In the meantime (since waiting isn't the most pleasant thing to do), does your GF's school offer arts, theatre, or music classes (for Bagrut)? Any reason why she shouldn't take that? If that's not possible, her parents clearly want her to have a good Bagrut, right? (Since you say they want her to be a doctor?) That's something she should do, whatever career she wants to pursue later. Good grades open doors: she'd get more choices of where to serve in the army, it would be easier for her to get a scholarship if she decides to go for any kind of higher education, it will look good in her CV. She's in a hard situation, certainly, but she can at least make the best of it.

Something else your GF can try to do is involve a teacher she trusts, get the teacher to talk to her parents about what she wants to do with her life. An adult in professional capacity might not be dismissed as easily as someone "young and inexperienced".

I hope this works out, for both of you!