Maggie is a privileged beatch
She only cares for herself.
First, she does not care that Mer and Alex have a history and that Mer had a reason not to say anything about the attack. Right or wrong, She and Alex are extremely close and she has to give Mer time to digest what had happened.
Maggie did that same thing to Weber when she told him that she was his daughter. The man just received a shock of his life. At an old age, he finds out that he has a child and the mother of his child is not alive to answer any questions. He's feeling guilty, shocked, angry, sad... all kinds of feelings. Yet Maggie whined about her own feelings and made him feel like *beep* I wished he had slapped her upside the head!