Both are on target developmentally. They're as happy and healthy as two little girls can be, even on opposite sides of the spectrum.
Winnie's stats
Height: 31 1/4 inches (27th percentile)
Weight: 20 pounds, 5 ounces (17th percentile)
Head: 19 inches (92nd percentile)
Miri's stats
Height: 43 1/2 inches (98th percentile)
Weight: 44 pounds (97th percentile)
Our big and tall Miriam received two legfuls of shots (I didn't mention the word "shot" until we were in the exam room and it was too late to run away), and our scrawny little Gwen received just one. Both of them settled down when the nurse brought them suckers.
I thought it was interesting when the med student accompanying our pediatrician asked some questions about Gwendolen:
"Does she talk?"
"How many words?"
"Does she string words together?"
Then the pediatrician announced that Winnie is advanced in her speech. They expect 18-month-olds to have a 5-15-word vocabulary; they expect 2-year-olds to have a 50-100-word vocabulary. And they don't expect kids to start stringing words together until they're 2.
I came home and told Seth that Winnie easily has at least 100 words that she says (without parroting). He was a little disbelieving, so we spent the evening remembering words we've heard her say, and we wrote a list. The list dominated our dinner table discussion.
The final count (and I don't think the list is yet complete): 112. I think that's why her head is so big in comparison to the rest of her body. Where else would she keep all the brains that store her words?