Hi, I have a cleaner who is meant to work 11 to 4, so 5 hours. She is often at least 15 mins late, but always leaves on the exact dot at 4pm. She literally can't get out fast enough. 15 mins I can let slide. However, today she came at 11.30. I was here today, so as I saw her leaving at 4 exactly, I said, "Oh thanks for everything... so just 4 and a half hours today then?" She said, "No, I was here 11.15." I told her it was actually 11.30 and that I don't want to sound fussy, but 30 mins is £10 and to me, if I started 30 mins late, I would make it up the other end. Not to mention, she was talking on her phone when she arrived and always takes about 20 mins to get started anyway (but I didn't mention this). This isn't the first time I've told her about timing. Her work is ok, but not great tbh. So I've sent her £90 this week instead of the usual £100. To me, it's just the principle of the matter, and when people are like this it doesn't sit well with me. I'm very flexible with her otherwise and she seems a nice person. AIBU?