KANSAS CITY, Mo. — Like everything else about 4-year-old Leah Southard, from her tumbling brown hair to her little pink and gray sneakers, the kid-size backpack she wears is darn cute.
And she wears it almost all the time, everywhere. She must be channeling Dora the Explorer, strangers comment with a smile.
Leah can’t remove her backpack for long because it’s her nutritional lifeline, what keeps her going, literally. Zipped inside is a pump and formula. Leah gets…