Honestly, the preface is fascinating. Charlotte is simultaneously trying to excuse and exult the perceived faults in Wuthering Heights. She sounds both apologetic for and proud of her sister, and I really appreciated the context she provides. Here's my favorite line, because girl, same:

"My sister's disposition was not naturally gregarious; circumstances favoured and fostered her tendency to seclusion; except to go to church or take a walk on the hills, she rarely crossed the threshold of home. Though her feeling for the people round was benevolent, intercourse with them she never sought... And yet, she knew them."