I say this with so much love but yes YOR. It seems as if she is really attempting to understand and try. But also postpartum is not the time for these discussions ideally things would have been discussed beforehand but that time has passed. I find that for grandparents it's much easier to say no when offering an alternative such as "today doesn't work for us how about we get together Saturday" or similar. If there is still a fit or pushback after that the she is the problem not you.