Lady Davers is Mr. B's sister. Overall, her friends and family think she's a good egg, with the rep of being a good and kind friend and a devoted sister. As Mr. B notes, "She was a dutiful Daughter, is a good Wife; she is bountiful to her Servants, firm in her Friendships, charitable to the Poor, and, I believe, never any Sister better loved a Brother, than she me" (92.189).
We're not so sure. According to Mrs. Peters (a friend of the family), Lady Davers shares her brother's temper—and his fondness for abusing servants:
Lady Davers, when a Maiden, was always vastly passionate; but a very good Lady when it was over. And she'd make nothing of slapping her Maids about, and begging their Pardons afterwards, if they took it patiently; otherwise, she used to say The Creatures were even with her. (92.129)
So, she's totally a nice lady … except when she's slapping her maids. And she'll definitely apologize … as long as they ask for one.
Yeah. Real nice, Lady.
Like a lot of siblings, Lady Davers and Mr. B have their issues. In fact, an epic quarrel about Pamela threatens to end their relationship. When she hears rumors that Mr. B is getting a little too friendly with his servants, Lady Davers dresses him down via an uber-harsh letter that gets him really mad.
Naturally, she's less concerned with his immorality than the fact that he's ruining their good family name. She writes: "Consider, Brother, that ours is no up-start Family; but is as ancient as the best in the Kingdom; and, for several Hundreds of Years, it has never been known that the Heirs of it have disgraced themselves by unequal Matches" (74.10). In other words, Lady Davers doesn't give a rat's behind about Pamela; all she cares about, for now, is that her brother refrain from disgracing the family by marrying servant.
Yeah, definitely not the kind of sister you keep inviting back to the family Thanksgiving.
In any case, you'll probably be shocked to hear that Mr. B doesn't appreciate the unsolicited advice. Not one to suffer being ignored, Lady Davers shows up at the Lincolnshire house to demand answers—and discovers that Pamela and Mr. B are already married. A lot of bad behavior follows, including some unsolicited slapping and a lot of nasty insults.
But even Lady Davers can change. Once she calms down and realizes Pamela's many virtues, Lady Davers drops the snob act and comes to love Pamela like a sister. (And you know how sisters love each other, right?)