I haven’t been able to watch yet, currently just reading this thread to catch up a bit, but it sounds to me that the defense just didn’t have anything to ask. From the tweets and comments here, it sounds like she was forthcoming and credible.
it doesn’t seem like she tried to blame Karen or clear Karen. I’m guessing her testimony must be pretty consistent in all reports, the Grand Jury, and to the Feds, and her phone records didn’t show anything inconsistent with her testimony, so the defense is letting her testimony stand as is.
I’m not a lawyer of course, but this seems like a smart move on their part. It sure does make it clear that their focus is on the people at 34 Fairview that night and not just everyone the prosecution calls.
I agree with everything written here; I also think that her emotion about John's death was credible and probably moving to the jury, so the defense would rather not elicit more of that with their questioning.