The former Blossom star admits she was left "stunned and horrified" after a gunman opened fire and killed 20 kindergarten students and six members of staff at Sandy Hook Elementary School in her hometown of Newtown.
Von Oy then discovered some of the parents who lost their young children were her old high school friends, and the vigil residents staged to honour the fallen was held at the church where she recently christened her daughter Gray.
The star has written a blog column as a show of "love and support" for her hometown, and she's urging fellow Americans to pray for Newtown as it grieves.
In the touching tribute posted on People.com, she writes, "Friday's massacre in Newtown has affected me in a profoundly personal way, as I have a unique perspective on the town... I am blessed to have grown up there.
"My family still lives in Newtown and, in my heart of hearts, I still consider myself one of its residents. I am fiercely proud to say I was born and raised in Newtown. It is where I was brought home from the hospital, attended my first day of kindergarten, learned to ride my bike and climbed my first tree.
"As I watched President Obama's press conference, I sobbed as he mentioned that the children who died had their whole lives ahead of them: graduations, weddings, having children of their own. I have celebrated every one of those milestones in Newtown. I graduated from Newtown High School, got married two years ago in a bed and breakfast on its Main Street, and recently had my daughter christened at St. Rose, where the vigil was held Friday evening.
"I grieve for the parents who lost their beautiful, innocent babies; some of them were friends from high school."
She closes her post: "I know, with absolute certainty, the residents of Newtown will rise up with love and strength in the face of their suffering. When you think of my hometown, I hope you'll think beyond this moment in its history.
"There aren't enough prayers to ease their pain, but I'm giving it all I've got, regardless. It is all I have to give, and I hope you'll join me. Beyond that, there are no words."