She's likely a senior citizen trying to protect her support mechanisms. If he loses, she loses - money! Ever wonder why SS is called the third rail of politics? It's because some old people would boil and serve up their progeny to keep their subsistence. Actually there's not just some; there are many - they're called AARP members.
She hasn’t always been a senior citizen. This went on for many years. Now their adopted son says he was abused.
I don’t disagree that she cares about protecting her gravy train in her senior years.
I’m adding that apparently she never did care about what was going on.