All charges were representative, covering multiple violent incidents over a two-year period.
Judge Phillips said the acceptance of guilt came shortly before trial and Matthews explained she wanted her daughters to avoid having to give evidence.
Aside from that, the judge said, there was no clear expression of contrition.
"She shows absolutely no remorse," he said.
The impact on the younger daughter was revealed through a statement written by her new caregiver with whom she had lived for the last year.
They described the victim's eating habits as "badly distorted".
She told them she went days and weeks without food, was too scared to ask for some and coped by drinking "lots of water".
For three months, the court heard, the victim had to be slowly reintroduced to food, with very small amounts.
She was now eating and sleeping properly and had had head lice removed.
"It would appear to me she was for a lengthy period of time in a position where she was fearful, frightened, not being properly cared for and it's taken a long time for her wellbeing and spiritual health . . . to be improved," the judge said.
"It's an indictment, really, upon you, Ms Matthews."
According to court documents, violence against the older teenage girl began in January 2016 and featured kicks and punches to the face and body.
Matthews would also pull the victim's hair and strangle her.
The court heard of one incident, featuring the younger girl, in which she left a jersey at home.
Matthews slapped and hit the girl repeatedly in the car as well as pulling her hair and punching her in the arm.
When they returned to pick up the garment, the mother again slapped and kicked the girl, leaving her bruised.
Following another argument some months later, Matthews kicked the victim repeatedly in the leg then made her stand in the corner of the room for several hours before allowing her to go to sleep at 1am.
Defence counsel Andrew Dawson stressed his client had no previous convictions and had been nursing her mother through a terminal illness at the time of the offending.
He said Matthews had given much time and energy to various community groups and was willing to address the underlying causes of the offending.
Judge Phillips said it was only good fortune the victims were not more seriously injured. The psychological repercussions could be devastating, though.
"It's a concern to me that we will not know the impact on either of these two young women of those many acts of violence until they themselves are mothers," he said.
Matthews' application for permanent name suppression was declined.
