No, Awai Onna is not based of Hachishaku-sama, but she's probably based of the urban legend of: Taka Onna
Taka Onna are frequently spotted peering into windows of places where current romantic activity are taking place, they like to scare and harasses their victims.
The name "Taka Onna" means "Tall Woman", that kinda makes sense, because Taka Onna appears as an ordinary woman most of the time, but they have the power to enlongate their body several meters high, this ability is kinda similar to the ability that Juliosan (an brazilian urban legend of a spirit of a boy that got drowned in a bathroom) haves.