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?