VANCOUVER -- As many families settle in for the holidays, Aliyah Ramirez-Bernard is grieving for her 16-year-old sister.

The Vancouver siblings, whose mother died earlier this year, were heading home from a family visit in Edmonton when Ramirez-Bernard lost control on Highway 16. They struck a van, which sent their car rolling towards a ditch.

Her sister Rainbow Skye Bernard – a bright, funny teenager who was just beginning to plan her future – was pronounced dead at the scene.

Ramirez-Bernard, the older of the two siblings, said she had been caring for Rainbow while the teenager finished high school, and they did everything together.

"She was my rock. She held me together," Ramirez-Bernard told CTV News in a tearful phone interview from Alberta on Tuesday. "She was my best friend."

As tragic as the accident was, it could have been even worse – Ramirez-Bernard is 32 weeks pregnant, and was initially terrified that something had happened to the baby.

The mother-to-be was airlifted to hospital after the crash with serious injuries, but has since learned that her child, at least, is healthy.

"They told me she was perfect, no trauma was caused to her. I think it was just a miracle we made it out alive," Ramirez-Bernard said.

She was planning to name the child Ember June Bernard, after their mother, but has now decided to call her Ember-Skye June Bernard – a tribute to both of the beloved relatives her daughter will never meet in person.

"I'm always going to tell her about her auntie and how much she loved her," Ramirez-Bernard said. "She was really excited for the baby to come."

Ramirez-Bernard was released from hospital on Monday, and is set to fly home on Christmas. She said she hasn't been able to think straight since the accident, and has requested privacy moving forward as she mourns.

News of Rainbow's death prompted an outpouring of grief on social media this week, and an online fundraiser was set up to help the family deal with funeral arrangements.

"It's hard to think of a world without Rainbow," one mourner wrote. "This beautiful young lady always had a soft caring heart."

Police said the roads on Highway 16 were icy on Sunday afternoon when the sisters were heading home from Edmonton. There were six people in the van they struck, all B.C. residents, but none were seriously hurt. Authorities said they were viewed by paramedics at the scene and released.

The collision forced authorities to close the highway outside Jasper for several hours. Witnesses who ended up trapped in traffic told CTV News road conditions in the area were treacherous.

"A lot of the drivers were saying they were spinning out," said Amy McKenzie, a truck driver who was heading home with her husband when they encountered the crash scene.

"It's terrible, especially this time of year."