Two teenaged girls who pleaded guilty to manslaughter and car theft in a botched carjacking that left a woman decapitated last year have been sentenced to two years in custody plus one year conditional supervision in the community.

But with time served that means the teens will serve another year in custody before their conditional sentence starts.

Roberta McIvor (Facebook)

Justice Heather Pullan handed down her decision in a Portage la Prairie courtroom today.

32-year-old Roberta Dawn McIvor was killed in Sandy Bay First Nation near Portage la Prairie in the incident last year.

Court heard she passed out in her car after a night of drinking.

The two teens, then 17 and 15, stole her car.

They tried to push her out but she got tangled in the seatbelt and was dragged down the road and eventually decapitated.

Both teens have been in custody since then.

The crown asked for the maximum penalty of three years.

Defence lawyer Greg Brodsky who represents the older teen asked for a minimum of one more day in custody for her.

'These girls should have gotten a longer time.'—Cindy Rubio, McIvor's mother

The other defence lawyer asked that his client get some time so she can be transitioned into child welfare care.

Roberta McIvor's mother Cindy Rubio is outraged by the sentences. She said justice has not been served.

"It tears me apart. I am so sorry (but) these girls should have gotten a longer time."

Rubio said she's still angry, even though the teens said they were sorry in court.

"I didn't even listen to the apologies from those girls because I know they are just made up," she said. "That's why I walked out of the court room."

The court was moved from Amaranth to Portage la Prairie because of threats of violence against the teens.