When my family visit my wife's family we stay in their house as guests. Her sisters will come into the bedroom we stay in to chat to her and I'm usually present and may chat to me wearing the headscarf and loose dress but no abaya.
Islamically I'm a non mahram to them even though I'm closely related (their sister's husband) so is it permitted for us to sit in the same room and chat (but never alone such as just 1 sister and me) if they wear the headscarf and loose dress? The other problem is that I really like one of the sisters so it can be a test to just chat without observing her beauty.
Interestingly they cover their faces when they go out in public but for close male non-mahram relatives will show the face in the house wearing a headscarf.