Why did Bubby, grandma, always say that? And does it really have to do with the evil eye? Is this evil eye a cousin of walking under ladders with black cats on a Friday the thirteenth? The answers, in order, are: Because she loved you. Yes, but with an explanation. No.
Kenahora, although everyone thinks is a Yiddish word is actually three words slurred together in Yinglish -- the vibrant language of Native Americans of the Lower East Side: kein, the Yiddish word for no or negating, ayin Hebrew for eye, and hara, Hebrew for Evil.
Now think back to when she used it: "Such a sheine punim, kenahora." "You've grown, kenahora." "He's making money hand over fist, kenahora." (you should only be so lucky)