User ChocBanana explains that she and her husband are “seriously struggling for money at the moment, as in all our food is coming from the local community food scheme and I haven’t paid my phone bill in two months.”

The Mumsnet user says that it was recently her sister-in-law’s birthday.

“Not a significant one, 53 I think,” she said. “They live away and I literally didn’t have enough money to send her a card (a card plus a stamp or a loaf of bread was my choice).”

She explains that she sent a message on Facebook, and asked her husband to send a text.

“His phone and internet is paid by work, so still on. He wrote ‘Happy birthday, have a lovely day, look forward to seeing you all soon.’”

The drama arose when her mother called her saying her sister-in-law was “gutted that I didn’t bother with her birthday and now they are saying it might “make it awkward” for Christmas.”

With her mother calling for an apology, “and a family row brewing on top of everything else” the Mumsnet user asked if she is being unreasonable.

She received overwhelming support online, 87 percent of Mumsnet users voting that ChocBanana was not being unreasonable.

User lifeinthehills said: “I would explain but not apologize.”

StoppinBy commented: “Brief explanation done in a way that hopefully makes her feel bad for being ridiculous would be my choice of ‘apology.’”

Sheilascarface wrote: “Surely not that close if none of them know you can’t afford food. Nothing to apologize for.”

Relationship coaches Orna and Matthew Walters had some sympathy for the mother and sister-in-law.

“In times of stress every human will revert back to old behavioral strategies (no matter your age),” the Walters told Newsweek, via email. “When it comes to family there are often unspoken expectations and when someone is disappointed it can cause a rift.

“An apology is warranted if you’ve hurt someone’s feelings, even if it was due to their unrealistic expectations. That’s because when you love someone you allow them to have their own experience. The closer you are to that person, the more wiggle room they get.

“Think of yourself as the center of a dartboard—the bull’s eye—and your relationships are people in the circles around you working from closest to acquaintances.

“Family is not automatically in an inner circle. The people closest to you are your allies who you’re able to be emotionally authentic with, and who value you.”

Newsweek was not able to verify the details of the case.