In the light novel continuity, Malty had her body destroyed in Volume 19, but her soul was saved.

Does malty s Melromarc die?

Ironically, none of the heroes would take her in as their party member because of her own actions against them. Furious that no one would take her in, she decided to commit suicide rather than being sent to Faubley as the King's “toy,” but Naofumi prevented her from taking her own life.

Does malty get punished?

When the Shield Hero's name was cleared, the queen gave the choice of punishment for Malty to her greatest victim. ... After been talked down, her punishment was having her completely stripped of her royal status and her name changed to "Bitch."