Who do you think has more to lose in discovery—Andrew Breitbart or Shirley? I would think her.
As for her only real goal, you are more charitable than I am. I suspect it is getting still more money through lawsuits.
I don't see any real downside for her in the the discovery process. Contrary to what you see on television, discovery isn't a open fishing license to subpoena any available record.
OTOH, Sherrod would probably be given some latitude to explore what Breitbart's motivations were, and to uncover what other people he was conversing with immediately prior to and subsequent to his publishing the story, after all , intent is an element of any defamation case.
"I suspect it is getting still more money through lawsuits."
I wouldn't say there's an absence of a profit motive on Sherrod's part, she might look to score a quick buck from Breitbart desire to quickly settle as a nuisance claim. However, as I said, she has virtually no chance of prevailing at trial (or on appeal), and any competent attorney would have told her that. Of course, if she gets generous discovery motions for Brietbart, she'll be the hero for the left, and I'm sure well-compensated by charitable leftist givers.