Nobody knew just how much she had saved until she died and left $7 million to Lake Forest College, her alma mater.
"You know, you just liked her because of who she was. She was just a great lady, but very unassuming. So it was a tremendous shock to find out – a happy shock -- that she could do this," her friend Carolyn Kinney said.
Groner found ways to save money. She shopped for clothes at rummage sales and walked places instead of buying a car.
"Everybody loved Grace. She was quiet, she was witty, she was sharp as a tack. And she very quietly took care of people. She wanted to right by people," Rev. Christine Chakoian said.
She lived in a one-bedroom house in Lake Forest and worked for Abbott Laboratories as a secretary for 43 years. Groner never felt the urge to keep up with the lavish Lake Forest lifestyle, but she did splurge occasionally.
Groner began donating small amounts of money toward small scholarship programs at the college, and always said she planned on donating more after passing away, but nobody expected her contribution to be in the millions.
The source of her wealth, it turns out, emanates from $180 stock purchase she made in 1935. She consistently reinvested her earnings and grew the purchase into a $7 million fortune.
The money will help about 1,300 Lake Forest students pursue internships and study-abroad programs that may have been out of reach without Groner’s hefty donation.
Aside from the $7 million donation, she also left her small house to the college, which will house scholarship winners who benefitted from her donation.
This story has been updated with original reporting from NBC 5.