Other creatures you control get +1/+0.
Whenever a nontoken creature you control dies, Judith, the Scourge Diva deals 1 damage to any target.
If Judith dies at the same time as one or more other nontoken creatures you control, Judith's ability triggers for each of them.
If your life total is brought to 0 or less at the same time that nontoken creatures you control are dealt lethal damage, you lose the game before Judith's triggered ability goes on the stack.
Judith's last ability triggers when Judith dies if it's not a token.