My mum has an appointment tomorrow at the time she would normally be picking my brother up from school. This afternoon she has asked me, his older sister, to pick him up in my car. Normally I would be happy to do this, but tomorrow I have plans that I would have to cancel to pick up my brother. I've said that at 17 he should be capable of walking down the hill for 15 minutes to the bus stop for a 10 minute bus journey that will drop him literally outside our house. My mum disagrees, saying it would be fine if he was used to it, but he's only done it once or twice before. Who is being unreasonable?