(Nick Galifianakis/For The Washington Post)

Adapted from an online discussion.

Dear Carolyn: I have two children, ages 3 and 6. Last year my 3-year-old was diagnosed with a rare disease, one that we are incredibly fortunate has a cure, but with considerable treatment. For most of this time, my 6-year-old lived with my sister and her family. This allowed my husband and me to focus on treatment.

Now that both of my children are at home, I noticed the attitude and behavior of my 6-year-old is very different and clearly my sister runs her household in a much more relaxed way than I do, with more processed foods, no set meal times and lax bed times. My 6-year-old is strongly resisting getting back into the routine of our house. I approached my sister asking her more about her household, and she made a comment about how the last year was hard on their family, and she had to cut some corners.

This made me see red. The last year was hard on HER?! My child was in the hospital for a year and she thinks last year was difficult for them? We ended up getting into a huge argument, and a lot of emotional things were said.

Now that I’ve cooled off somewhat, how do I get my household back on track? And secondly, how can I improve my relationship with my sister?

Sister

Sister: Nope: Repairing your relationship with your sister comes first, because family trumps your schedule.

And you fix that by apologizing to her. Promptly, profusely and with a detailed acknowledgment that you got so caught up in how awful this was for you that you failed to appreciate how hard it must have been for her.

Because, hello? She took your child in for a year! It must have been really, really hard for her. Not only because caring for a very young child is difficult, but also because the child you handed over was no doubt rattled — even traumatized. (Will refer to child as Six hereafter, for simplicity’s sake.) First, Six had a seriously ill sibling, along with seriously stressed Mom and Dad, yet at the time had only a 5-year-old’s language and emotional resources to handle it. Then Six has to transition to a different home, where Six no doubt missed you terribly. This isn’t “Whee, an overnight at Grandma’s!” this is [whispering adults] [scary-sick sibling] BOOM moving in with Auntie.

Auntie, meanwhile, was a hero. She took Six out of a stressful situation and did what she had to do to make it work, apparently without a peep of complaint until (1) well after the fact and (2) you lit the fuse by asking “about her household.” Translation: judged her for favor-doing that was beneath your standards.

And, yeah, after moving heaven and earth to help you through your very real and wrenching family crisis, a person is going to rear up at even the whiff of that [bleep].

So, that’s what you have to fix, in person I hope, when you admit to taking her profound generosity for granted. That your sister rested her heroics on the pillars of microwave snax and a 10 p.m. wrap-up of “Frozen” doesn’t take a thing away from the fact that she really came through. She was your godsend. Treat her accordingly.

Write to Carolyn Hax at tellme@washpost.com. Get her column delivered to your inbox each morning at http://bit.ly/haxpost.