Of course, this is something you can research yourself (i.e. Google your city/state/federal laws) -- but I'm going to take a guess: it is up to the doctor.
Now, the *doctor* may try to shift blame/responsibility on the government (e.g. "I would LOVE to prescribe you Norco, but unfortunately, my hands are tied") so that you won't be mad at him/her, so that you'll still go to them for their off-label Spinal Steroid shots or whatnot...
But I think if you come across as a real 'salt-of-the-earth' type of a person, you were desperate for pain relief, you didn't want to bother them for more pills (because you know they are addictive), and you heard so many people talk about herbal cannabinoids being safer (talking 'medically' like that comes across better than, "hey man, the weed's like, really awesome"), but you've done lots of soul-searching and want a chance to earn their trust again....
Anyway, good luck. (And don't call it 'weed' in front of the doctor :-)
When you signed on with your pain specialist did she know about your card and that you used medical marijuana some times? If she did not know this and you signed the contract stating that you would not use anything without her consent then yes, she most likely has the right to refuse prescribing your pain medication.
Maybe you can set up an appointment and tell her about your card, if she doesn't already know, and tell her you will sign another contract saying you will not use marijuana again.
I'm sorry you're going through this. With all of these new laws and the contracts we pain patients get so confused about what we can and can not do.