I keep on eye on my cadence but vary it alot. Typical cruising on the flat is between 85-95, but I switch up a lot because it changes how your muscles work. I sometimes shift to my biggest gear, stand up and just "walk" the bike for a while before returning to a high cadence.

I think I remember reading somewhere that it is not uncommon for women to spin at a slightly slower cadence than men. I have definitely found that doing superspin intervals on a trainer has made me a stronger rider.