I don't know how is best to handle it.
She has quite an active social life and has a diary as she is always going on about her diary and says she couldn't manage without it.
however, every single time we make arrangements she says 'Remind me, or I'll forget'. We have planned to go out later today and when she phoned to make the plans she said 'remind me, or I'll forget'. This time I'm not going to remind her. Why should I? She clearly doesn't think I'm worth noting about in her diary.
What do I do if she doesn't turn up today? What can I say to her next time she says it to me? I find it a bit insulting tbh