Actually, though Pusskin, I think Spring Cleaning was something everybody did before we had so many cleaning gadgets, e.g. putting the rugs out in the spring and beating them to death and having the good weather to wash all the curtains etc and dry them outside - no dry cleaners about.
I always think I am going to do a lot of cleaning when the good weather comes and then I go out in the garden instead because gardening is much nicer than housework. So, in effect, the cleaning doesn't get done winter, spring or summer or winter!! ;o)
Pusskin, is your sister OK and her daughter, C.?