Queensland car thieves will face longer prison sentences, and more time if they steal cars while armed or at night or boast about it on social, under a fresh crackdown on youth crime following the alleged murder of a mother in her home.

Premier Annastacia Palaszczuk will change the laws next year after British mother-of-two Emma Lovell was stabbed while allegedly defending her home from two teenagers on Boxing Day night.

Under the plan, car thieves will face 10 years behind bars, or 14 if they steal cars at night, threaten or use violence, are armed or pretend to be armed, are with others, or damage or threaten property.

Judges will also have to take into account a child offender’s previous bail history, crimes and track record when sentencing, and slap youth offenders with increased penalties if they boast about their crimes on social media.

“Community safety has to come first here and we stand with the community members across Queensland,” Ms Palaszczuk said on Thursday.

“I’ll tell you now, we know a lot of people aren’t going to like some of these announcements I’m making today and I’m going to stand by them, and people will be able to judge us on that at the next election.”

The government will also spend almost $10 million to speed up the sentencing of children before courts in Brisbane, Townsville, Southport and Cairns, and spend the same amount trailing 20,000 engine immobilisers in Townsville, Cairns and Mount Isa.

Ms Lovell’s killing came 14 months into the Queensland government’s youth crime crackdown, in which laws were changed to ensure courts made a presumption against bail for serious, repeat child offenders and have the power to fit them with GPS trackers.

Ms Lovell’s devastated husband Lee, who was stabbed in the back in what he called a “terrifying” encounter, has called for policy changes to prevent other families from suffering like he and his two daughters are.

“We’re not the only family to be affected by this and things need to change,” he told A Current Affair on Wednesday night.

More than 36,000 people have also signed a petition calling for mandatory bail refusal “violent home invaders who repeat offend that use or have weapons regardless of age”.

The Lovells had reportedly been in Australia for more than 10 years but were originally from Ipswich in Britain.

A fundraiser set up for the Lovell family had raised more than $57,000 of its $75,000 target by 12.30pm on Thursday.

-AAP