Matthew Foerster was found guilty in April and began serving a life sentence for the death of Taylor Van Diest.
She was found near death on some train tracks on Halloween night in 2011.
Her mother, Marie Van Diest, said Friday that the appeal is part two of a nightmare and she can't stand the thought of the whole case resurfacing.
"I was under the assumption that it was very cut and dried and a stellar job had been done putting him away. So we're waiting with our breath held and we'll see what happens.
Foerster's father, Stephen Foerster, was sentenced in May to three years in prison for trying to help his son evade police.
B.C. Supreme Court in Kelowna, B.C., heard Foerster bought his son identification and helped him escape to Ontario.
Van Diest was dressed as a zombie and walking to a friend's house at about 6:30 p.m. on the night she was killed.
She was found barely alive two hours later, lying near railway tracks, her head resting on a steel pipe.
Van Diest suffered six blows to the head, a pathologist testified, and one of them fractured her skull and caused a severe brain injury.
Foerster's lawyer, Lisa Helps, told the jury that her client's actions amounted to manslaughter, not first-degree murder. She said Foerster wanted to have sex with Van Diest, but when she fought back he pushed her down, causing her to hit her head on a steal pipe.
Helps said there could have been a sexual proposition that didn't go very well, but all of that was possibly consensual.
But Crown lawyer Iain Currie said the fact that Foerster hit Van Diest on the head six times with a heavy flashlight, tightened a shoelace around her neck and drove to Vernon, where he threw evidence in a dumpster, left little doubt that he intended to kill her.
He said Foerster's DNA was found under one of Van Diest's fingernails and that she'd scratched his neck trying to fend him off. (CKFR, The Canadian Press)