Yes thats very true. Many people in our area have granny flats built onto their houses to accomodate their parents.
I know in years to come I'm going to get stuck doing that as well, as its so damn expensive putting the elderly into those homes, and I may as well increase the value of my property by putting on a shack for them to live in and care for them myself.
I do draw the line at wiping asses though, be it my mum or hers, I ain't wiping no ones ass.