Kate of "Fantastic Four"

MARA

This actress played a superhero with a last name that sounds like a bitter citrus fruit.

This clue refers to Kate Mara, the actress who played Sue Storm (the Invisible Woman) in the 2015 Fantastic Four reboot. The first name "Kate" is given directly, and "Mara" is her last name, which fits the answer. It’s a straightforward reference to her role in the superhero film, with no wordplay involved.