Congratulations, Erin! I'm sorry to hear of the scary ER visit and hope everything is now ok.
This is a beautiful essay and captures much of what I also went through. We, too, have 2 wonderful daughters and had the same logistical questions (as well as the idea/curiosity of what it would be like if a third were a boy). Ultimately, we chose not to try for a third.
I hope I never regret that decision. In the meantime, I make the most of my time with my nieces and nephew (or at least I did pre-pandemic). There's a great relief in being able to go home and sleep 8 hours after a long day babysitting. LOL!