CBC reports 21-year-old Cheyenne Rose Antoine pleaded guilty to killing 18-year-old Brittney Gargol in 2015. They got into an argument that same night.
But police soon began to think those posts were only a ruse to throw them off Antoine's trail.
Robin Ritter, a Crown prosecutor, said Antoine poses a threat to public safety.
A selfie posted on Facebook hours before Gargol's body was found showed the smiling friends and crucially Antoine wearing the same belt.
However, police were suspicious of the story and used Facebook in an attempt to establish the pair's movements on the night of Brittney's death.
Chillingly, she had tried to cover her tracks on social media by posting a status hours after her death asking where Gargol was. After getting drunk, Antoine showed up to her friend's house and confessed about the her murder to Gargol. Antoine had led police on a wild goose chase, telling them that the pair had visited several different bars before Gargol left with a man.
At her court appearance Monday, Antoine's lawyer, Lisa Watson, said her client suffered through sexual, emotional and physical abuse as she grew up in foster care, CTV reported.
Antoine was sentenced to seven years in jail for manslaughter. She was sentenced to seven years in prison. The now convicted killer said she hit Gargol and then strangled her with the belt. Both girls were using alcohol and drugs on the fateful night, police said.
"No doubt this young women has issues...and because of those issues she is risky", said Ritter.
Before Antoine was condemned, Gargol's close relative gave a casualty affect explanation to the court.
"I will never forgive myself", Antoine said in a statement. I'm really, really sorry.
"Most days we can't stop thinking about Brittney what happened that night, what she must have felt fighting for her life", Jennifer Gargol said.
She was five years old at the time of the killing.