Hello drfields24. Thanks for sharing your experience with your sisteras it is not an uncommon reaction. Try not to let her response bother you too much as it is just another one of those 'instinctive', knee-jerk reactions that people make when they are not really thinking things through.
I did try to capture this concept in rhyming verse way back in 2012 in a poem entilted 'HOW ARE YOU? ( BRIEF RESPONSES)' - Do we tell them the truth or do we lie? Or do we simply ask them WHY? Once the conversational door has been opened, we enter into a minefield of potentially offensive interaction. The poem will be on my profile somewhere as I have posted all this stuff at the point when it was pertinent to me.
One of the great things about writing down my feelings is that it tends to free me up from the emotional crap which tends to be associated with the event and I can move on without giving it much more thought. I hope you can do the same.
If you sister asks a similar question again as to what you are doing or how you are, you can quite honestly answer that you feel that she 'really doesn't want to know!'
Best wishes
Bill