Advice re trialling with your Mum is good. My parents are now 92 and 93. They keep telling me that getting in and out of our Discovery 5 (lowered to access height) is easier than with Mrs F’s Mini Clubman. They talk about the seat bolsters and the sill width. It is counter-intuitive to me but there you go.
BTW - a Honda Jazz is a great wagon for carting crumblies about. The way the rear seats fold to enable a folded wheel chair to be slid in through a back door is awesome.