She can legally load and shoot from the vehicle if it isn't moving or running only if she has a disabled hunter permit from the WDFW, other wise she can't.
Go t the WDFW website and look up disabled hunter permit application form which part of has to be filled out and signed by a doctor, they have been tightening up the definitions of a disabled hunter for the last couple of years because there was a lot of abuse of the designation by some people.