OA Confusion

I've been doing OA. Or at least going to OA/HOW meetings. It has been interesting and has given me a lot to think about and made me take a closer look at how I function right now, not how I want to function or should function. It's interesting. I will try to write more about it in the future, but right now I want to get off my chest an incident that happened this morning. A person whom I had met through OA a number of years ago but did not know well needed a ride to a HOW meeting this morning. I was tired but made very sure that I got to the metro station to pick her up on time. And she wasn't there. And she didn't show up (I thought) for the next half hour, despite me circling the block several times, parking, wandering around looking for her, getting coffee etc. I eventually gave up, feeling a bit annoyed but mostly compassionate for her, concluding that she must have been having a really hard morning. I didn't get a call from her. I went ahead and went to the meeting, which went fine. I then heard from her about 3 hours later when she left a voicemail asking where I had been. I called her back and we chatted about what had happened. I still have absolutely no idea how we missed each other. None. We were, apparently, both at the same area at the same time, but totally didn't see each other. She also waited for a half hour. Anyway, I feel like I did something wrong. Like I should have waited longer or looked harder for her. I know I should have brought her phone number with me (and she didn't have mine either, so that was a mutual problem), but I don't know why I feel guilty. I guess because I had promised that I would drive her to this meeting and I ultimately failed to do that, despite trying to. I'm hoping writing this down will make me feel a bit better. I know, logically, I did nothing wrong and really did try. But I still feel bad. Because I know she needed/wanted this meeting. Anyway, we set a more definite meeting place for next week and are going to try again. I hope it works better!