(CNN) - One of Wendy Killian's young students was ill. Eight-year-old Nicole Miller was born with a genetic disorder and in need of a kidney transplant. The girl was exhausted and often missed class, although her parents did their best to keep her up to speed.
During a parent-teacher conference, Killian asked Nicole's mom, what does your daughter need in a donor?
As she listed off the requirements for a match, "I just kept thinking, 'Huh. That's me,'" said Killian, a teacher at Mansfield Christian School in Ohio.
Now, she's preparing her students to work with a substitute teacher, and preparing her own sons to face her recuperation.
When the hospital calls, Killian will be giving Nicole a kidney.