Characters and frame story/ "Wuthering Heights"

"And that minx, Catherine Linton, or Earnshaw, or however she was called- she must have been a challenging- wicked little soul."  This describes the time when Lockwood found the writing on a wall or bench that said these two different names for Catherine.  The character list is actually a bit confusing.  However, this story of all the characters relation is told by Nelly to Lockwood.  This is an example of a frame story because it is a story within a story.  Nelly is explaining the history of Wuthering Heights because Lockwood had a nightmare.  The characters start with Catherine and Heathcliff when they were younger and worked for Hindly.  Then, Catherine marries Edgar.  They then have a daughter, who they name Catherine.  A few hours later after the birth, the older Catherine dies.  Nelly is like a servant, and she is to take care of Catherine.  Also, Isabella is Catherine's sister-in-law, and then married Heathcliff.  However, she was very unhappy after they got married.  Also, there are two families who were like enemies at the beginning: the Lintons and Earnshaws.  However, at the end, they became civil with each other.