Thank you so much for your letter. What a surprise to hear from you. My initial response, my ONLY response, is this:
Thank you for (inadvertently, of course) confirming that our decision to have only one child is truly "for our good". Slipping into the habits and "norms" from my childhood would be all too seductive otherwise. This way? My choices are MY choices, rightwrongindifferent. This unfamiliar path keeps me alert, non-complacent.
That is my (chosen) take home message.
Because of you, I am who I am.
In spite of you, I'll be who I'm supposed to be.