She targeted not just the OW but also two innocent people (OW's husband and child). I wonder how she justifies that? The only pity is that the mother and sister, arguably more culpable than her, aren't also sitting in a prison cell.
I do agree that it's possible to blame BOTH parties for the affair, although the brunt of any anger should have been directed at the father. I do wonder about the marriage though - the father was married to a nutter who thought nothing of instrumentalising her children for vengeance 12 years after the fact.
Now one is in prison and the other has lost her job as a police officer. Both daughters will probably struggle to find gainful employment now and all because one or both parents shared FAR too much detail with the girls about their marital troubles and the mother then proceeded to egg on her daughters into criminality.
Even now there's no remorse or regret on the girls' part (report I read said the gobby sister butted into court proceedings). So yes, am glad she has 3 years to sit and reflect on her behaviour away from her mother's contaminating influence.