I have a lot of mixed feelings about this case.
First, in the interview I saw, the mum was regretful about her actions, she understood herself why she did it but it took her away into prison at a time the boys were vulnerable and she also said having taken a life weighed very heavily on her. She did not seem remotely jubilant about what she'd done (unlike some on here).
Second, her campaign for these offenders not to be able to change their names and for their crimes to be visible to those in the community, I agree with. This guy's offending record was horrendous, under a different name. Plus him being bailed after 24 convictions- what? Who is protecting the public?
Third, there's lots on here saying they would do the same, but actually almost no-one does, it's extremely unpleasant to confront an abuser, and then stab them. It's a bit like when we discuss old age and everyone reckons they'll be off to Dignitas, very few go through with these things. This case is on the news as it is highly unusual. I feel I could pull the trigger to kill an abuser but probably not stab them to death, I wouldn't stab anyone to death unless they came at me with a knife (I have been in a struggle with an offender and fought very hard so know how I'm likely to react).
Fourth, and I'm sure the mum would agree, once you get vigilantism, you open up a can of worms. The justice system can't even get it right every time and convicts the innocent and offenders get off. Put that system in the hands of people driven by emotion and without evidence- it's a recipe for disaster.
I do have sympathy for her though as she looks quite traumatised as well you would if you ended up stabbing someone, your kids were abused and you spent time in prison. Poor lady.