I really seem to have opened a can of worms and I can assure everyone that I'm aware of visible and non-visible disabilities - part of my job in another life. Granny23 - a close friend of DH was unable to get a badge for his wife (Alzheimers) being told there was nothing physical that prevented her walking as she was suffering from a psychological disorder! Mind boggling?? I think what comes through is that a total reassessment of disability is long overdue. It's not so long ago that people with disabilities were seen as housebound and with 'no lives'. My Uncle was 'lucky' to get a single seater Invalid Carriage (remember those?). It did give him some independence, but presumably it was thought a disabled person would always be 'alone' so one seat was enough. The Company repairing DD's wheelchair would give us a 3 day window to visit, as they expected her to be sitting at home all day. Whilst one disability shouldn't be seen as more important than another I think the whole thing is a mine field. MiL after a slight stroke was encouraged to apply for AA at the lower level - we were very surprised when she got it, She didn't need it and walked miles to and from the shops every day - whilst I know of other's - truly deserving, who have applied, been refused, appealed, refused again and given up. Same thing with DLA and Carer's Allowance too.
DiscoDancer1975 - you have echoed one of the points in an earlier message - DD doesn't need a space so close to the shops as she can and does self propel for miles (if necessary). What she advocates is reserved spaces for badge holders closer to shops etc, for those who can only walk short distances for whatever reason (visible or not) but an area set aside with wider spaces so that wheelchair/electric scooter users can transfer safely from their vehicles although I can see a problem with wheelchair users who need an attendant, where a longish distance might be a problem for them? Also wheelchairs don't move well on snow, so that could be problem too, as carparks don't get cleared much now. A minefield you'll agree.
nanna8 - my daughter also gets a lot of flak from people, as she doesn't seem disabled until the chair appears. She was even criticised at a Carol Service in Durham Cathedral for not standing up during the service, as she'd transferred out of her chair, so she wouldn't be an obstacle and her chair wasn't visible!
Again, thank you for all your comments.