A circle hostess is a woman who organizes and leads social gatherings within her community or social circle. She is responsible for planning events, inviting guests, and ensuring that everyone has a good time. This role is often associated with traditional women's social clubs or organizations.

The singular possessive is hostess's.

The plural possessive is hostesses'.

Hostess is a noun.

Male is host.
Female is hostess.

The correct singular possessive form for the noun hostess is hostess's.