My mother-in-law has been through quite a few. She has emphysema so struggles to walk for any distance at all.
They have gone thought all sorts of different ones. Small ones that fit in the car easily to their current behemoth that looks more comfortable & has better range, but won’t fit in the car.
She’s quite (a lot) overweight so the small ones really take a hammering and the battery life suffers. She also doesn’t feel very safe on the smaller wheels.
Your relative really needs to sit down & write down a list of requirements. If it needs to fit into the car, it will instantly rule a lot of them out. If it’s only for local trips from home then you can get away with something bulkier, with bigger wheels & batteries etc.
A lot of them seem to be very expensive for what they are & the technology seems pretty archaic.