CHICAGO (CBS) – Could you help solve a murder mystery?

Ramona Shelton was shot to death on Thursday outside her home in Thornton Township.

As CBS 2’s Mai Martinez reports, Shelton’s family is hoping someone out there can help find her killer.

“We are devastated because Ramona was literally the cornerstone of our family,” said Shelton’s sister, Amanda Anderson.

Anderson is still struggling to understand why someone would kill her sister, 37-year-old Ramona Shelton.

“She was a loving mother of six children,” Anderson said. “She has a blended family.”

She was also dedicated to community service and helping children, even serving as a cheer coach for a few years.

“She took people into her home,” Anderson said. “She cared for people and children that did not even belong to her.”

Last Thursday, Shelton was found shot to death insider her car parked in front of her home on South Paxton Avenue in Thornton Township.

CBS: Any idea why someone would want to kill her?

“That is the $100,000 question of the day. We don’t know,” Anderson said. “I think that is so important for me and my family to get answers to that. Who and Why? Because she does not have any enemies.”

According to Cook County Sheriff’s Police Detectives, Shelton was last seen around 11:35 a.m. leaving her home to get lunch for contractors who were working on it.

When she did not return after a couple of hours, the contractors walked out and found her shot to death in her car around 2 p.m.

Her family is pleading with the public to help police.

“Someone knows something,” Anderson said. “If you saw someone run across the street that looked out of the ordinary, we’re asking you to talk about it.”

They also have this message for her killer: “We will not rest until justice is found for Ramona Shelton.”

Visitation for Ramona Shelton will be Wednesday from 6 p.m. to 9 p.m. at Leaks and Sons Funeral Home in Country Club Hills. Her funeral will be Thursday in Munster, Indiana.

If you have any information on this case, you are asked to call the Cook County Sheriff’s Office.