Well, I think it can be construed as rude but it would depend upon the circumstances.
If she invited all of the neighbors and you were the only one not invited, then it was definitely rude.
But if the party consisted of only her family members or her co-workers (and you are neither), then it's not so much a question of rudeness as it is bad timing.
I'd let it go, for now. If you feel you were slighted, just don't share any more of your recipes with her!
