I 100% KNOW I am being unreasonable, which is why I'm not posting in AIBU.
MIL is 80. She is a bit frail after a fall a few years ago (and yes, I appreciate this is mean, but part of the problem is she refused to do the physiotherapy that the doctors wanted her to do at the time which, naturally, has had a longer-term impact on her mobility).
She has also always been someone who has this strange and unusual combination of, on the one hand being independent and competent and on the other, ridiculously helpless and fearful. Depending on the situation. In particular, new things have always stressed her out. I suspect she has pretty severe inattentive ADHD (like at least one of her grandchildren, and probably at least one of her children) that, being a woman of a certain age, was never even vaguely diagnosed and so she just got on with it and taught herself tools to manage. One of these is being very resistant to new situations/change and needing excessive preparation (eg, when she travels, she starts packing a MONTH before).
I say all this because I think this impacts massively our current situation. She promised DD MONTHS ago that she'd take her shopping. It's something they've always enjoyed doing together (stopping often for cake!). But MIL has been ill, had a flare up of her sore leg etc so it hasn't happened. We recently discovered that a shopping mall a bit further away from us than our usual options has free mobility scooters if pre booked. DD was thrilled and called MIL immediately to tell her that we could go to tihs place instead as that way she could have a mobility scooter....
.... MIL said no. She doesnt think she could use a mobility scooter.
I am so annoyed and upset on DD's behalf. I KNOW I'm being unfair. She's old, and frail, and this is completely outside of her comfort zone. But it's so frustrating. And full transparency - this is not the first time she has let our DC down for this sort of reason (in fact, it's not even the second, third or fourth time....)
My dad tells me I must be patient. I agree. But HOW?!