These kids - Arianna Talmage, 6, Aidan Talmage, 10, and Tyler Talmage, 14 - are all dead now.
No information has been released about how the four died.
They also told the Associated Press that the family had recently moved into the newly-renovated home but they rarely saw Volk because she worked odd hours. A handgun was recovered at the scene.
An officer discovered the our bodies Thursday morning after directors at Lewis and Clark Elementary College requested for a welfare verify on the dwelling within the south of the town.
The house had been cordoned off by crime tape on Thursday.
Volk set up a GoFundMe page about eight days ago, citing that herself along with her children suffered from mental illness.
What's already known is that school administrators asked the officer to conduct a welfare check on the home after the younger children didn't arrive at school, a practice Zimmel said Grand Forks schools use on a "case by case basis". All had gunshot wounds; police say they aren't looking for any suspects.
"I work full time but my wages have recently been garnished for medical bills", she wrote.
She had a job at Cirrus Aircraft, but she got help from food pantries.
Grand Forks County court documents show a collection agency won three civil judgments totaling about $3,750 against an Astra F. Volk in the last six months of 2017 for unpaid medical bills. The garage door was opened more than halfway, and a pink child's bicycle was overturned in the yard.
Police aren't yet saying what happened.
"This is scary", Stevens said.
Assistant Superintendent of the Grand Forks Public School District Jody Thompson said, the school is working hard to pick up the pieces by providing the resources needed, for all affected by this tragedy.