A good friend of mine and I have been flirting and joking and teasing each other more and more recently. It's never bothered me before that she is taller but it seems like we might be heading into a dating relationship. Will she think less of me and is there anything I can do to effect that?
As long as it doesn't bother you I bet it won't bother her. I was with my ex wife for 10 years and she was 5'11" and I'm 5'8". I never let this bother me nor did it intimidate me. Also be sure to let her know that it's also ok for her to wear heels around you. Be confident in who you are and in the relationship and this won't be an issue.
If she were taller, wouldn't she have to look down on you? As far as thinking less of you, I like to think you'd know if someone discriminates against you for something as minuscule as height, it is their loss, and you should be grateful you weeded that shallow person out of your possibilities, and move on. Why would you want to do anything to change the heart and opinion of a shallow person? Just find someone who already appreciates you for who you are more so than what you could be.