How old was ethel mertz on Lucy show?

Ethel Mertz, played by Vivian Vance, was never given a specific age on "I Love Lucy." While the character was often described as "middle-aged," the show itself didn't stick to a particular age for any of the characters, allowing the humor to transcend specific age boundaries.

However, we can infer a general age range based on:

* Vivian Vance's age: She was born in 1909 and played Ethel from 1951 to 1957. This would make her around 42-48 years old during the show's run.

* The character's relationships: Ethel was portrayed as being in her prime years, married with a husband older than herself. She was Lucy's close friend and confidante, suggesting a similar age.

* The time period: The show is set in the 1950s, where "middle-aged" was often perceived as starting earlier than it is today.

Overall, it's safe to assume Ethel Mertz was in her late 30s to early 40s during the "I Love Lucy" series.