Do not be so sure that if a secular Jewish aunt had knocked herself out to make a meal for her visiting observant niece (“newly” observing, from aunt’s point of view), she would automatically take “no” for an answer when it came time to eat what she made because she used hotel butter and hadn’t gotten her steaks from a kosher deli. Maybe…but then again, maybe not. Maybe Auntie would get her nose bent out of shape because her niece was being a pain in the hind end in order to show everyone she had become Miss More-Jewish-Than-You.
Do you remember the line from My Big Fat Greek Wedding, when Aunt Voula was told that the groom, Ian, didn’t eat meat?
What do you mean he don’t eat no meat? Oh, that’s okay. I make lamb.
And we all know that every traditional Greek cook knows how to make a meat-free meal, too!
The Church, which gives the discipline of abstinence, does not look at it the way you describe, but allows Catholics to dispense themselves from the obligation to abstain on Fridays in Lent* if it seems necessary in order to avoid giving offense*. Not because it is convenient to us, because maybe we’d rather abstain, but because it is accomodating to someone else. If we, the faithful, add a burden over and above that in preference of abstinence over being gracious, the strife or hurt feelings will be on our heads, not the Church’s.
Still, I think it premature to presume that the aunt won’t make accomodation. It depends very much on the family. It is so common these days for hostesses to make inquires about dietary restrictions that in the end this may be a total non-issue.