Karen Ramirez was tragically killed in a single-vehicle crash near the Hunter Valley village of Sandy Hollow in March this year.

She left behind seven children - Melissa Stevens (30), Katrina Bulmer (26, a teacher at Forbes Public School), Mitchell Bulmer (24), twins Isabella and Gabriella Ramirez (15), Jarrod Ramirez (12) and Anastacia Smith (5).

Since her death, $16,000 has been raised to help make the family's Wheelers Lane home, part of which had sunk, habitable again, with Mitchell putting his life on hold to do the work.

But between Saturday afternoon and late morning on Sunday, thieves broke into the front window of the house and cut a padlock on a back gate, stealing tools, a vacuum cleaner and even an outdoor setting.

Melissa Stevens said it was devastating to be robbed of basically everything that was left.

"It looks like they have backed up a vehicle and loaded it up with the things and then driven off," Ms Stevens said.

"Until forensics have been in and looked we can't get a real guide as to how much stuff is missing but Mitchell's tools are probably worth $1500-$2000."

It's a "kick in the guts" for a family who have already suffered so much.

The four youngest children had been staying with different family members around Dubbo after insurance wouldn't cover the damage to the family home.

They were also involved in the crash that killed their mother, but escaped serious injury.

"It's a kick in the guts because people have been working so hard to try and get the house to a point where it can be lived in again," Ms Stevens said.

"People from the TAFE have been working there the past couple of weeks and we've had great support, and then something like this happens."

Orana Local Area Command acting inspector Steven Munn said the break-in took place between 4pm on Saturday and 11.30am Sunday, and police are urging anyone with information to come forward.

Neighbours have been canvassed in relation to the incident, Acting Inspector Munn said, and investigations into the matter are ongoing.

Anyone with information in relation to the weekend's break-in are urged to call Crime Stoppers on 1800 333 000.

Anyone wishing to assist the family can do so by visiting the GoFundMe page.