I watched BBC's TV adaptation of Jane Austen's Sense and Sensibility last night. I REALLY regret not picking up the book, it's TONS better than Pride and Prejudice (which I found boring.)
If you don't know the story, there are basically two sisters, practical Elinor Dashwood (Sense) and flighty Marianne (sensibility). Their mother is the second wife of Mr. Dashwood and they have another little sister named Margaret. When their father dies, he leaves his entire estate to the younger Mr. Henry Dashwood, the son of his first wife. Even though Henry promises to take care of his half-sisters, he is easily swayed by greed and his scheming wife, Fanny Ferrars. Mrs. Dashwood and her daughters are reduced to an impoverished state and forced to move to a tiny cottage.
Why I think Elinor is an ISFJ (without revealing any spoilers!): Elinor takes it upon herself to be the pillar of strength for her family during their time of grief and turmoil. Her mother tends to be more emotional, like Marianne, so Elinor has to take charge in household matters at times. Due to the wonderful portrayal by the actress, you can really see that despite her calm and cool demanour, Elinor is an extremely passionate and emotional young lady. (The author describes her as being emotional, but being able to govern her feelings.) Most of the time, she's rather under appreciated, by her family, friends, and even the readers/audience. I'm sure most of us would prefer the volatile but more interesting Marianne at first. I certainly did. But later on, Elinor's qualities endeared to me.
Elinor and Marianne are the classic Fe/Fi divide. Elinor is conventional and civil to everyone, even to the point of suffering in silence over her love for Edward. Marianne is very open with her feelings, and eskews all social conventions.