If someone "knows" something or wants something in how I live, they need to tell me of it sooner than later, before rather than after.
I wrote to my Gramma saying I thought she tried to kill my mom with cancer by making annoying noises on her plate. My mom needs peace and quiet. I told my dad I didn't even want her to come..! I wanted to explain why I snapped at her or got upset. I didn't shout.
They think since I brought it up to apologize it "means something." They are digging in my past looking for things to justify a decision of pleasure against me in their older age.
Part of it was it was in a long letter on an expensive card. There is not anything wrong. It is a vague matter of preference to get settled. It's probably wrong to think against it. Yet, it can be easily fixed by not mentioning it and seeing if they want it mentioned therefore. Just say something else vaguely but not it itself, in its place.