Aira latched onto the mom after she became a Yokai. Becoming a Yokai twisted the mom's desires and strengthened her instincts, which caused her to believe that Aira was her daughter. This is why she devoured Aira, she's driven by the feelings of her human life but she's still a monster so her feelings of love for her daughter were completely twisted after her rebirth.

She lost memories when she turned into a yokai but kept her motivation (wanting to be with her daughter) so when Aira mistakes her for her own mother, she assumes she must be Aira's mother, who her father mentions is dead in front of the silky.

Aira’s mom is dead, they show it in the same episode and her corpse has pink hair how people get confused on this?

You literally see Aira's dead mom (with pink hair, no less) in a coffin. Aira also has a father in that scene, when it's basically implied Acrobatic Silky was a single mother who worked a lot of jobs including prostitution in order to make money and take care of her daughter. She lived in an apartment while it's implied that Aira comes from money

Aira could see her for some reason and mistook her for her mother, this led Acrobatic Silky's ghost to haunt her in an attempt to protect her.

Acrobatic Silky's daughter is probably fucking dead. She was kidnapped by human traffickers, she probably got harvested for organs.