Aunt Polly

Origin
Mary, Tom and Sid's aunt, who is the sister of their dead mother. Brothers, Tom and Sid, live with Aunt Polly and her other niece, Mary. Despite the relentless discipline and spiritual guidance she dispenses, she comes off as a caring and noble character. When Tom points out that nobody seems to care about Huck's being alive after they were both presumed dead, Aunt Polly generously gives her love to Huck as well.
 * "And so they shall. I'm glad to see him, poor motherless thing!" and the loving attentions Aunt Polly lavished upon him were the one thing capable of making him more uncomfortable than he was before.

The last impression we get of Aunt Polly is of a similar nature:
 * "There was something about aunt Polly's manner, when she kissed Tom, that swept away his low spirits and made him light hearted and happy again."

Public Domain Appearances
Book:
 * The Adventures of Tom Sawyer
 * The Adventures of Huckeberry Finn

Film:
 * Tom Sawyer (1917)
 * Huck and Tom (1918)
 * Huckleberry Finn (1920)