If we were handing out Mother of the Year awards, Mrs. Rearden would not be a finalist. Not even close. She might even be disqualified. Mrs. Rearden has taken in the looters' moral system so completely that she even mistreats her older son, since he's basically forfeited his right to receive charity and kindness due to his own moral code.
Mrs. Rearden is also hopelessly confused by her son. She seems to live in a bubble of wealth, without any conception of how exactly Hank contributes to her lifestyle. In a rather funny scene, Mrs. Rearden demonstrates her obliviousness and her blind faith in Hank's Houdini-like ability to magically "fix" things:
"I don't understand it," said his mother. "Jail? Did you just say jail, Lillian? Henry, are you going to jail?"
"I might be."
"But that's ridiculous! Do something about it."
"I don't know. I don't understand any of it. Respectable people don't go to jail. Do something. You've always known what to do about business." (126.96.36.199-3)
The philosophical conflict between Mrs. Rearden and her son defines their relationship much more completely than their blood relationship. In fact, we often get the sense that Mrs. Rearden is only Philip's mother and scarcely has anything to do with Hank at all. We get no flashbacks of Hank's childhood, where we presume his mother played some role, and we get the sense that there is very little affection between them.
"That's your cruelty, that's what's mean and selfish about you. If you loved your brother, you'd give him a job he didn't deserve, precisely because he didn't deserve it – that would be true love and kindness and brotherhood." (188.8.131.52)
Mrs. Rearden resents her older son on behalf of her younger son, who clearly is on the same page as her in terms of values and ideas.