Am wondering why she considers she has 'abused' sinemet. Is this because she has read it, because she has gone over the prescribed dose, or she has not been compliant in some way? If it is helping her condition and keeps her moving I wonder about such a resistance to taking it.

I would have thought a move sideways tapering one medication while increasing the other would be a more standard approach to meds.

I would want a second opinion, but that is me.

I have only your description to go by, and from what you say this is not a medication that is having no effect. In which case after 7 years most people would have problems of abrupt withdrawal of any medication, and it is hard to see how in this case there would be no problems associated with it.