Where exactly am I required to be naked instead of bathing suit/spa attire in the facility ? My sister isn't comfortable with that kinda thing and i wanna know what the deal is before going..

Right after you pay, you walk into the locker area which leads to either the nude part or you can bypass that and go straight upstairs to the general area

In the women area downstairs only, upstairs is the regular spa where everyone has a bathing suit on.

You only have to be naked in the women's only section. They have a few pools and 2 saunas to use. Also when getting treatment or massages you will be undressed. Everywhere else is communal and requires clothing they provide or bathing suit.

There is nowhere in the spa where u go naked