Pom Klementieff was 31 in Avengers: Infinity War when she played the character 'Mantis'.
That was over 6 years ago in 2018.
Today she is 38, and has starred in 33 movies in total, 13 of those since Avengers: Infinity War was released.
In Avengers: Infinity War, I think Pom Klementieff looks: