This essay made me think of my mom. My brother and I are 14 months apart and my earliest memory is crying because she was holding him and couldn't hold both of us at the same time. Like your girls, we grew up close but I think about how challenging it must have been for my mom.
I barely survived parenting my kids (who are 3 years apart) with lots of help (my parents and in-laws came over weekly!). I always wondered how my mom survived raising 2 kids under 2 without any help from my dad (he was in a PhD program) or anyone else. She was halfway around the world from her mom and friends.
Thanks for providing such a heartfelt perspective on your experience.