It's a bit complicated. Jean Grey's fate varies depending on the comic storyline and continuity. Sometimes she's dead, but often there are plot devices that bring her back.
It's not straightforward to say she was evil. The Scarlet Witch's behavior in the comics was influenced by many factors, and her intentions weren't always malicious. Sometimes her powers caused unintended consequences that were seen as negative.
Scarlet Witch is indeed a mutant in the comic universe. Her mutant powers give her unique capabilities and play a significant role in many storylines. However, the extent and nature of her powers have evolved and changed over time.
The Scarlet Witch's character in the comics is complex. She has moments of both good and bad, depending on the storyline and her motivations. So, it's not a simple yes or no answer to whether she's evil.