I think everyone has basic Intution maybe even a touch of some type of psychic powers, and or some gut reaction. Was the woman really psychic is one of the mysteries of life, how do we know really.
As to the summerland, summerlin part it was subtlely explained in the ep.
GRISSOM: Sedona said Claire Wallace was "In Summerland," not buried in Summerlin.
GREG: What's Summerland?
GRISSOM: Pagans believe it's a mystical place where souls go to rest before they reincarnate.
GREG: So Jameson heard Summerlin ...
GRISSOM: Because he was desperate to solve the case. Then when Wallace heard Summerlin ... he assumed Sedona was the real deal.
GREG: The power of suggestion.
As to the summerland, summerlin part it was subtlely explained in the ep.
GRISSOM: Sedona said Claire Wallace was "In Summerland," not buried in Summerlin.
GREG: What's Summerland?
GRISSOM: Pagans believe it's a mystical place where souls go to rest before they reincarnate.
GREG: So Jameson heard Summerlin ...
GRISSOM: Because he was desperate to solve the case. Then when Wallace heard Summerlin ... he assumed Sedona was the real deal.
GREG: The power of suggestion.