Pretty sure they can't. We had connecting rooms at Pop for 3 of our 4 trips and had the same problem with my son as you had with your mother. They eventually ended up just making us some extra cards to be used just as room keys. Wasn't the best solution as my wife or I had to carry around a couple of cards for each of the kids but it solved the problem.
As for the connecting room issue - it never hurts to just ask them to switch your rooms if you get there and find they are not connected. We are not ones to whine or complain over little details, but on all 4 of our trips, we've had to talk to the front desk about our room locations after arriving and checking in. And again, it's not because we are just downright impossible people to please or anything, far from it. It was just we had made a room request while booking each trip through our CAA agent (all booked a year or more in advance) only to arrive and find they didn't really seem to honour it. We wouldn't have bothered if it wasn't for the fact that it concerned my mother-in-law and her having a slight handicap. Each time, they were more than accommodating. Granted, it took a little while for them to switch everything over for us due to the fact that they had to get their manager and look to see what was available. But each time we ended up with exactly what we were looking for in the first place.
Like I said, we never complained or made a big stink about it. We just inquired and they accommodated us.