My five-year-old had her 18-month checkup today.
She's now 32 1/2 inches tall (75-90 percentile) and 22 pounds (25 percentile).
And she's completely healthy and completely normal.
...except the nurse who pinned her down for her four(!) shots kept saying, "Wow, she's strong. Strongest kid all day. Stronger than a three year old. She is so strong."
So, yeah. Apparently our string bean is freakishly strong.