k first i will say that i am an 'on time' person and hate being late and people who are late, it drives me nuts i think being late is superrude and inconsiderate
having sed that, in my experience, some people genuinely dont see lateness and timekeeping as important at all. like if
you turned up two hours later, this girl may not even think it is an issue cos in her life being on time is no biggie either way and she is just totally relaxed about it.
perhaps when making arrangements to meet you could include her in the decision making process? eg will X o'clock be too early for you to be ready? we can meet later if that is better for you..what is a good time for you to make it? perhaps you are setting times that are difficult for her to make because she has other commitments or it takes her X number of hours to get ready after work etc (it does take girls longer to get ready than guys - we dont look this beautiful accidentally even if we would like you to believe otherwise)
i think when you say 'lets meet at x time,' you think that is a definite arrangement with a definite time attached, but in hear head she
may hear 'lets meet up later this evening' ......to test this theory you could make a very specific arrangement where the time is very important, such as going to the cinema and meeting at 19:20. tell her you dont want to miss the beginning of the movie. be clear. if she is late, then she is either a person with terminally lateitis (ie she will never get better) in which case you will need to decide if you can live with that; or she doesnt care enuf about
you to make the effort - in which case move on.
finally i dont think you should show it bothers you. remember : people do what works, so if she is always late and there are no negative consequences, she will continue to be late. i like the other suggestion of texting her '5 mins and i'm off';its not as if you dont have anything better to do with your time if you try all the above and she is still inconsiderate, then just dont wait, and she has got herself all ready for nothing....she will soon learn