Judgment of eternal nature is not something we can do nor something we can comprehend. That is left to God, unless we too want to be victims of our own ignorance and reap the hell we condemned others to. The judgment spoken about in Matthew 7 is talking about when men take the place of God. We don't judge souls. Further down Jesus says swine and dogs when referring to people but that is a mortal judgment.

John 7:24 Judge with righteous judgment is also talking about our mortal affairs. Building a profile about someone and acting accordingly.

We rejoice that she is dead because her evil on Earth has stopped but we don't rejoice because for eternity her soul will suffer (if she is in fact suffering now ). If this still encourages you to cheer for the eternal suffering of others I encourage you to read Matthew ch.7