Hello CL - It must be quite a surprise for her, the fact that you are not accepting every one of her invitations. Has there been any change in her actions since you started this new strategy?
I like this 180 because you are genuinely looking at whether you will be happy with your decision, based on whether or not you feel you will be 'present'. Somewhere along the way, we start making choices that are right for us as individuals as well as the R. You may need to apply the same for her neices' piano recital, regardless of what the 'expectation' is. Would you be happy there, and therefore be a good companion to be with?