Just had a look at 1969 telephone directory on Ancestry (one of those rather useful but fairly well hidden resources on Ancestry). That gives just
Carlton Hotel, North Prom, Blackpool (that's the Best Western one above)
Carlton Private Hotel (Mr & Mrs D. Park), 64, Albert Rd, Blackpool
not the 343-347 Promenade Royal Carlton, so that's presumably post-1969.
The Albert Road one is really just a B&B and stands out on Albert Road as being tiny compared to its neighbours (see it on Google Street View) and unlikely to have a manageress, I would have thought.
So that leaves the North Promenade Carlton Hotel. That's much bigger and quite an imposing presence, and most likely to have had managers/manageresses for various departments.

Maybe this picture from the hotel
website might jog some family memories?