The author, Mackenzie, inundates Paltrow in the letter with sarcastic sympathy over the actress' recent comments to E! about how "easy" an office job is for parents versus being in movies.
Paltrow had spoken to E! News last week and said that she plans to take a break from acting in order to focus on her kids.
"I think it's different when you have an office job, because it's routine," Paltrow said. "You can do all the stuff in the morning and then you come home in the evening."
"When you're shooting a movie, they're like, 'We need you to go to Wisconsin for two weeks,'" the actress continued. "Then you work 14 hours a day and that part of it is very difficult. I think to have a regular job and be a mom is not as, of course there are challenges, but it's not like being on set."
"As a mother of a toddler, I couldn't agree more!" Mackenzie begins her response.
"'Thank God I don't make millions filming one movie per year' is what I say to myself pretty much every morning as I wait on a windy Metro-North platform, about to begin my 45-minute commute into the city," the mother continues.
"We [working mothers] have a competition to see who has it easier," she says sardonically. "Is it the female breadwinners who work around the clock to make sure their mortgages get paid ... What about the moms with "regular" 9-to-5 jobs, who are penalized when their kids are sick and they don't have backup child care?"
"Gwyneth, you've figured out the secret of working parents ever," Mackenzie ends. "Livin' la vida desk job is a breeze compared to the 14-hour days of a film set ... Who in New York -- especially those in the finance, law and tech professions -- could possibly work 14 whole hours?"
Paltrow has often been criticized as being out-of-touch due to her celebrity status. Many consider the healthy lifestyle the actress touts as unsustainable for the average person.
Read the entire letter here.