All of her impressive feats happened in her realm. She easily beat Pandora, and the Trinity of Sin had a hard time dealing with her. Both characters are in a neutral realm.
Depends on the incarnation. At times, she's Vandal Savage level, and others, a fraction of her can destroy the multiverse at a whim. She, along with Barry Allen was also responsible for Flashpoint. JM Demeties also stated that her, Phantom Stranger, and the Question were all cosmic related.