Yes, there's a limit. My Mom laughs about a story from her childhood. She was breastfed by my grandmother until she could talk. One day in the middle of church, my Mom screamed out, "Momma, I want titty!" My grandmother was horrified and told my grandfather on the way home, "We're weaning her TODAY!"
Mayim sounds like an extremist. The OB's wife...hmmm...I need to ask for more information. Can you imagine?!
No solid food until a year? Gee. You mentioned that Lauren sleeps better now that she eats solids. Spencer does, too. On top of that, breast milk is metabolized more quickly than formula (if you think about formula, it makes sense...formula is sludge-like compared to breast milk).
I will always appreciate the NP/LC easing my anxiety about adding formula. Do I wish I could breastfeed exclusively? Of course. But it would have been way too impractical for me. Spencer has only had one minor illness since he was born - an ear infection and low grade fever in November - so whatever we're doing is working fine.
Just wait until Lauren begins daycare, Mrs. A. You'll likely run into super-competitive moms. I actually had one say to me this week, "Spencer is already sitting up so well and my Simon is still a little wobbly. I'm worried about him." I assured her that babies develop at their own pace and unless there's some glaring deficiency, he's fine. My niece didn't walk or cut a tooth until after a year. She's now a 4th grader, just tested into the gifted program and is a champion swimmer. Her slight delays obviously didn't hinder her ultimate development.