As a perpetually late person and partner to a perpetually late person, I’d say go with the “tell her the wrong time” thing, on events that are important to you. My friends did that with me for years. I knew they did it, I knew why, it worked. My mom also used to do that to my dad. Again, he knew, it worked, no problem.
You probably want to mention it ahead of time, but I don’t see where she’s got grounds to get upset over it if she knows she has a problem. By mention it, I mean during that friendly discussion Mahna Mahna talks about. Just tell her that you’ll be doing this sometimes, in order to get places on time when it’s important to you. Don’t do it every time, or she might start taking it into account. :eek: If she does get pissed, then I’d say she’s probably not worth your time.
OTOH, you might need to reconsider your perceptions and needs also, and put them up for discussion at the same time. If you perceive this behavior as lack of respect or caring for you (which many people do, although I think they’re usually wrong), then you’re going to be more upset over it than if you perceive it as an unfortunate quirk. That’s something that needs to be worked out between you.
Why is it important to you that she get home by a specific, pre-arranged time? In my family, we have much more general timeframes. For instance, “I’ll be home early” means somewhere before 10pm, “I’ll be home late” means somewhere between 10pm and 1am, and “I’ll be home really late” means the wee hours of the morning. (More or less - none of those are actual “official” timeslots, just a general notion.) If ETA moves from one slot to another, a phone call takes care of it.
There have been a couple of occasions where someone wasn’t paying attention and didn’t make that phone call. Although the other family members were pissed off (and worried - this was before we had cell phones), it wasn’t a major issue. Apologies and promises to do better (and we have) were all that was needed.
Oh, and leaving without her is also OK. We do this regularly when we’re going to a non-time-specific event (most of the things we go to aren’t on a strict schedule). If someone is running behind, the others will go ahead and leave. It relieves the frustration of those who are ready and relieves the pressure on those who are running late. Generally makes the whole event more enjoyable. Again, you want to discuss this in advance, but it’s certainly a viable technique.