The mother is trying to absolve herself from the worst decision she has ever made, by taking in the ‘immigrant child’. ‘See, he is a good boy so therefore, my daughter is not dead because I was stupid and hired an illegal alien.’
Guilt and a painful loss is causing her to rationalize in a way that protects her.
Sounds to me like a personal death wish...like she subconsciously wants to suffer the same fate as her daughter.