I have a weekly catch-up with two people from my old team (Sarah and Kate) as we all committed to lose weight together, so we meet up to check on each other's progress. It's a casual thing, like meeting briefly for coffee, but without the coffee. Sarah and I didn't think it was necessary, but Kate insisted that we do it. I created a meeting invite, so all three of us get the reminder 15 minutes before we're due to catch up.
Kate has missed the last 4 catch-ups. Each time, she never said anything, didn't mention missing it (her status was set to "away" in our office IM client, so we couldn't even message her to ask if she could still make it). We message her phone, but she doesn't reply until hours later. The first two times, I asked her if the time was OK, whether we needed to move it, or if there's anything I could change to make it easier for her to show up. She said everything was fine. The third and fourth times, I didn't say anything, she never responded, and it's almost like the meeting didn't exist to her. I found out later from Sarah that she booked a doctor's appointment during the same time as our 4th catch-up, but she never messaged me to reschedule.
As I'm no longer on that team, I have to make a trip to a different floor to Kate's desk, and it's frustrating waiting around for her not knowing whether she'll show up or not. During the last catch-up, I messaged Sarah asking if Kate was at her desk, and when she replied, "No", I didn't bother going. What's even more frustrating is that she'll message me and Sarah hours later asking to meet up saying that she's now free. Except we are still at work, and I have long since context-shifted away and am working on other things.
With these catch-ups, Sarah and I have agreed that we're not going to bother meeting up anymore, but I would like to talk to Kate about her behaviour, as I think it's unprofessional (skipping meetings without saying anything), and also really rude. I would like to get her to show up, or at least notify someone if she can't make it.
Edit to add: She also does this with work-related meetings (either showing up late, or not at all), and Sarah says she often has to prompt her, "Hey Kate, aren't you supposed to be in the X meeting?". But since I'm not her boss, nor on her team, I don't know if it's my place to talk to her about that as well.