Labels will expect demos to be either "crap" (for simple songwriters) to "retail ready" in the case of independent producers (not "producer" like sequencer, but "producer" like the rest of the industry).
Jewel and artists of her ilk can pretty much send in cassette tapes made on a child's toy recorder. It's going to be judged on the quality of the writing. Then the producer will find the right musicians and arrnagers to knock it into shape for commercial release.
Indie artists who are also the performers need to sound as "finished" as possible to the labels. Retail-ready packaging included in many cases. They're not presenting compositions - They're presenting a recording artist. The label wants songs from songwriters and artists that don't need a lot of "hand-holding" from performing and recording artists.
So yes, if you don't have the mixing skills, find someone who does. Then find a mastering engineer to polish it up and send it off.
