My father was a doctor (passed away several years ago), and my mom is a registered nurse; I came from a family where books were always in ample supply (especially medical books-lol). Most of the premeds I have met don't have physician parents, but they seem to be doing as well nonetheless.
I worked my first semester of college, a seasonal (miserable) retail job, but I haven't been working since. I do think that working affected my GPA negatively, but I think that can be counterbalanced by choosing hours wisely (I had come straight out of high school, and was starry-eyed and naive and not as assertive about calling off/asking for less hours as I should have been). It has been my experience that most of my premed friends are working either part-time or even full-time, though. I have a scholarship that covers about half of tuition, and also I go to school in NV which has one of the cheapest universities (second only to Washington, D.C.)