I work a rotating shift pattern. I'd been invited to a hen night on Saturday when I should have been working. I wasn't that bothered about going, but I asked a colleague if she was free, and could she swap shifts with me. She said this was fine. I was under the impression that it suited her too. She did Saturday night and I did her shift on Sunday night. Yesterday, she e mailed me to say that her husband had been called into work, and she had used a babysitter which had cost her £30. She sent me her bank details. I have transferred the money. But, had she told me this on Saturday, I'd just have done my original shift myself since.
AIBU to find this a bit rude and odd?