Over the years I have read, from time to time, that she's not a very nice person to people she considers of no consequence or when she's not in front of a camera.
I found this fascinating thread that spans a few years, written by airline cabin and flight deck crews, talking about the famous and not so famous people who've been a passenger on their flights.
I found it fascinating, politicians, royalty, film stars, actors, groups and bands, dead and alive, are all in here and almost 100% of the time the personalty assessments agree. If you want a giggle, have a read.
http://www.pprune.org/archive/index.php/t-300180.html