Quads Born Identical Twins, but One Didn’t Survive. What Hurts Most 3 Years Later

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Ashley Ness' babies entered the world as quadruplets – and not just any quadruplets, but two sets of identical twins

Born three months premature, the quads spent about 10 weeks in the hospital before three of them were allowed to go home. But the fourth, a baby girl named Chesley, remained behind and died just shy of turning seven months old

“She’s never not a thought in my mind," Ness tells PEOPLE

The start of a school year is an anxious moment for any parent sending their kids off for the very first time. But for Ashley Ness , a mom of three 3 year olds, enrolling them for preschool carried added poignancy.

“When I brought the babies to school to do all the paperwork, I was standing behind them and all three of them were walking in, and that’s when it really hit me,”