Evelyn Eilers’ first birthday party had a lot of what most first birthday parties have: cake, balloons, presents. But Evelyn isn’t like most 1-year-olds. Born Sept. 9, 2023, she weighed just 8.46 ounces, making her the tiniest surviving baby in the United States. She came 17 weeks early and was in the neonatal intensive care unit at University of Iowa Health Care Stead Family Children’s Hospital…