Origin of blankety-blankreduplicated, reduplication of blank, noun
Blankety blank means she's cursing.
The definition of blankety-blank is an expression used when a person doesn't want to actually say swear-words or curse words, but would like to express the sentiment.
An example of blankety blank is what you would say when you pinch your finger in a drawer. You could say "this blankety-blank" drawer instead of using curse words to express your frustration.