My DH has a cousin who has TWICE forgotten to invite my stepson to important family occasions. Since all of my stepson's cousins were invited both times, I KNEW it had to be an oversight. I know that she is not a nasty person, and would never leave one person out on purpose. Both times I spoke up and called her, and both times my stepson got an invite. My stepson invited her and her whole family to his wedding, and they came. We have not harbored any ill feelings. She's not a ditz either, just a person with an overly-busy life. This stuff happens. It doesn't necessarily mean a thing.
-Nancy