Avila's mother says she does not know why her daughter was at the party or how she got there.
The teen girl lived in north suburban Highwood. Her body was found in North Chicago.
ABC7 is told no arrests have been made, but police have told the family that the area where Adriana was found is gang-infested and getting people to talk there will be difficult.
Meanwhile, the family says they don't know how the 14-year-old got to North Chicago to begin with.
"I just want them to drop the silence code. We just want to know what happened to my sister," sister Denise Avila said. "She was a good kid and didn't deserve this to happen to her."
The last time anyone saw Adriana was around 9 p.m. Saturday. A friend of hers walked her to a street corner just steps from the Highwood apartment she shared with her mom and three siblings.
The girl never made it home. She was shot and killed 13 miles away outside of a north Chicago house just after midnight, a place she had never been before.
"She said, 'This is my first time over here.' I was like, 'Girl, this isn't where you need to be or where you want to be.' She's like, 'I'm just here with friends. We're going to leave soon.' But soon never came," said witness Priscilla Brown.
Despite there being a lot of people on the street at the time, no one will admit to seeing who fired the shots. North Chicago police say by the time it was all over, three teenagers, including Adriana, had been shot. The other two have not been identified, but they survived their injuries.
"We have no idea how she got there. She was not gang-affiliated. She was such a good kid. She was a good student, a big help around the house. She was like my mom, she was like my mom. She was like a second mom," Denise Avila said. "She was always there and would clean up and make sure everyone had done their homework."
Adriana Avila was a freshman at Highwood Park High School. Her sister saysid she was excited about the cooking and photography classes she was taking. However, now, the family is planning a funeral, while the Lake County Major Crimes Task Force is heading up the investigation into who killed her.
North Chicago detectives are also part of the investigation.
ABC7 is told grief counselors are expected to be on hand at Highland Park High School Tuesday.