I saw THAT as her being an arrogant smart-ass, basically saying to Grassley "Up yours!".
I hope she pays, is all I can say.
She saved the letter as her ace in the hole, since Kavanaugh was doing well, she took a gamble and lost. She used Ford to raise money for the mid-terms, hoping it will help them to get the Senate back, and her sacred power. It is likely now, the Republicans will hold on to the Senate.