You provided crazy ideas. But i know as i look back at this an idea will jump out.
Twins are 80 yrs. ADDY'S grndma is dead. Other twin is very ill and dying so finding the connection is keeping her interest and alive inspite of health.
Addy has traveled from e coast to w coast to escape a traumatic experience.
I ve been listening to The girl in the spiderweb. A take off of the Millineum series. This author jumps all over whats taking place and gives incredible detail to the character's thoughts supositions as well as drawing out the storyline. Im not bored but since its audio and on cds I have to remember all the detail. Good exercise.

          Tina