So what kind impression does one get of a girl who only frequents Marina, Cow Hollow and Pac Heights bars?

.... hmm.. not sure.

One could ascertain several things... but only honestly, one shouldn't judge another person because they hang out at certain places.

Every person is evolving. People do things for a reason. As a single girl, safety can be found in good, clean places. Does anyone hang out on 3rd Street in the Bay View district?

Don't be prejudice.