Can a lady wear a hat indoors?
Is it appropriate for a woman to wear a sunhat indoors i.e. in a restaurant, a shopping mall, a grocery store or in a public building? I assume that it would be more acceptable for a woman to wear a sunhat (i.e. a large-brimmed sunhat) than it would be for a man to wear a casual baseball cap inside more public buildings and restaurants?
You are right. It is far more acceptable for a woman to wear a fashion hat, than it is for a man to wear any hat, indoors.
Generally speaking a woman may wear a hat indoors. The exceptions are: in an office or when it obstrudes someone else's view such as during a tennis match or a movie showing.
A lady would also remove her hat when it interferes with appropriate eye contact.