DD plays the clarinet . We currently rent one. I saw one going very cheaply on eBay, collection only, four miles from SIL but hundreds of miles from us. We will be seeing SIL at Christmas. She is child free by choice. (Her husband is a giant toddler but that's a whole other story!). I bought the clarinette immediately before anyone else could. This will very soon pay for itself. I rang SIL, asking if she could collect it for me please. DD is her only niece, it was four miles. I would have done that without question for anyone I know. I genuinely saw no problem although I agree it would have been more polite to ask first. However, waiting for SIL to answer the phone or return an email can take time. She has no kids and works part time. Thirty minutes to help someone who has helped her parents a fair bit seemed a reasonable ask.
She will collect the clarinet for us, I have been informed. However, I am not to assume she will help at any other time unless I have her full consent in advance.