Ahead of Christmas, Sara Shepard, a nurse and mother of two, picked up extra shifts at the St. Louis University Hospital in Missouri in the hopes her hard work would result in a present-filled holiday season for her kids. But on her way to work Saturday, the 31-year-old was tragically killed in a car accident.

“Sara had already picked out a Christmas list for the children,” Becca Hill, Sara’s sister-in-law, told Fox 2. “Her whole life was her kids, everything she did was for her kids.”

Shepard was killed Saturday around 6:30 p.m when a pickup truck collided into her vehicle, causing Shepard to drive off the road and strike a nearby guardrail.

It is not clear what caused the driver of the pickup to crash into Shepard. The truck driver and his passenger were transported to a local hospital with “moderate injuries.” Authorities are still investigating the accident, according to the news station.

The loss has been difficult for the family, Shepard’s brother, Dave Hill, told Fox 2. Their brother, James, reportedly died just seven months prior to Shepard’s accident.

“Her whole life was her kids, everything she did was for her kids.”

— Becca Hill

“We’ve learned a lot about grief through this whole process,” Becca said, adding Shepard’s son and daughter, who the news station did not identify, “are suffering the most of out all of this.”

“Our hearts are broken to hear of the sudden passing of Sara Shepard. Sara was the epitome of a nurse, talented, knowledgeable, compassionate and dedicated.  She was kind-hearted and an advocate for her patients. Sara will be dearly missed by all who knew her. Our thoughts and prayers are with her family at this time,” the St. Louis Hospital said in a statement to Fox 2.

A GoFundMe page for Shepard was created by her cousin, Angie McBride.

“Your contribution to this fund will help with putting Sara’s affairs in order, final arrangements, Christmas and future needs for her young children,” McBride wrote on the crowdfunding site.