These are the Torah's guidelines on how a woman is required to dress...
Please always consult (Just one) qualified Posek for special accommodations (Halachich authortity and only go to one, I recommend contacting Rabbi Toviah Singer, who specializes in Jewish outreach to gentiles). I don't know if the stuff about not praying with having visual contact with a woman who is not dressed properly applies to Noahides (Gentiles).
https://outreachjudaism.org/contact-us/ 