From her Twitter account:
What's this I hear, # Holder being tapped as possible Supreme? I'd work "fast and furious" to block that move!
— CatPing4Congress (@CatPing) September 26, 2014
First of all, there is no opening on the Supreme Court. It doesn't appear that, unless there's some unforeseen circumstance, that there will be an immediate opening on the Supreme Court. Thus, the point the entire situation is irrelevant to reality.
Secondly, Eric Holder would be a really good Supreme Court Justice, but he would be a really stupid nominee. He has as much of a chance of being confirmed as I do. Unless President Barack Obama wants a fight, which at this point, he might, I don't see him nominating Eric Holder as a Supreme Court Justice. There are much safer nominees for the President that won't spark a political tug of war.
Finally, and most importantly, Cat Ping is running against Andre Carson for a seat in the House. The Senate confirms Supreme Court nominees through its advise and consent responsibilities laid out in the U.S. Constitution. Thus, Ms. Ping would have nothing to say regarding Mr. Holder's long shot nomination for the Supreme Court.
Of course, she needs to get elected first, and that's the longest shot of all of this.