At first I took this personally but then I came to the conclusion that this person must have "morning" issues. I decided not to force it and I'm fine with the no-response mode.
But I feel kind of sorry for this person because she just seems put out - not just in the morning - but all the time.
Yeah, sometimes you have to 'act' a "Good morning," but eventually you can 'act' your way into a better attitude and that 'act' soon becomes who you are.
You can either 'act' your way to happy productivity or you can 'act' your life into misery.
It's entirely your choice.