Does Keima's mother know Elsie and/or Haqua's real identity?

Question

In TWGOK II episode 8, Haqua shows up claiming to be Katsuragi Keima's father's illegitimate daughter, just like when Elsie shows up in their house. His mother immediately leaves the house on her motorbike without listening to Haqua when she says that was only a joke.

After the ending song, Keima's mother is shown shouting in the phone to supposedly her husband, asking how many illegitimate child her husband has fathered and threatens to divorce him. But later she says that she was only joking, in a tone that suggests that she knows of Haqua's identity.

Does this means that she actually knows Elsie and/or Haqua's true identity?

Answer 1

I'm not aware of any further canon details or Word of God explanations, though I won't guarantee the latter doesn't exist.

There would be a difference between "knows her true identity, ie that she is a spiritual being from Hell", and "knows that she's not really her husband's daughter (but otherwise just assumes she's a human girl with feelings for her son)".

She probably just goes along with it in the end because she's ecstatic that her introverted NEET son is suddenly bringing (real) girls home with him, and she wants to give him some privacy and a chance to break out of his shell so he can establish real relationships with real people. She is shown at various points worrying about Keima's future, and that he would come home married to a cardboard cutout one day and just go crazy-hobo mode. As such it's consistent for her to jump at any chance to get Keima interacting regularly with a girl his age.