Was I Wrong to Give My Always-Late Friend a Fake Time?

I (20F) have a friend who is chronically late. I'm not talking about 5 or 10 minutes either. If we agree to meet at 6, she'll usually show up around 6:45 or 7. We've talked about it so many times, and every time she apologizes and says she'll do better. It's caused problems before. She was almost an hour late to another friend's birthday dinner and we lost our reservation. She was also late to a friend's going-away party and missed most of it because everyone had already started saying their goodbyes. Once she was supposed to pick me up for a doctor's appointment and showed up 50 minutes late, so I had to take an Uber and still ended up missing the appointment. I had to pay a cancellation fee to reschedule it, i can name atleast 20 such instances from the top of my head. The thing that really gets me is that if someone else is late, even by 10–15 minutes, she will sometimes make a huge deal about it. It's happened maybe twice, so I don't want to exaggerate it, but it definitely feels hypocritical given how often she's late herself. Atp, our friend group has basically learned to expect it from her. Last week, a few of us were going out for dinner. We had a reservation for 6:30, so I told everyone to be there by 6:15. She said she'd leave her house at 6. At 6:20 she texted saying she was "leaving now." I was honestly fed up, so I dm'ed her that the reservation was postponed at 7 instead. Everyone else knew what I'd done. We got there at 6:15, had dinner, and when she finally showed up at 7:35, she was obviously pissed that we'd already eaten. She asked why I'd lied to her, and I told her that when I give her the actual time, she doesn't show up until an hour later anyway. She said that was completely different and that I deliberately set her up to be late. She also said she trusted me to give her the correct time and that I had no right to "teach her a lesson." I told her i was tired of constantly waiting for her and having everyone else's plans revolve around her lateness. She called me manipulative and said she doesn't want to make plans with me anymore.