Supposedly she listen to a tape or whatever of the oral arguments, and wrote her decision.
Now if your asking me, do I believe that Ruth baby really listen to oral argument's, and wrote an opinion.
ANSWER: HELL NO!!!! She had one of her underlings write the opinion, she signed it.
It really doesn't matter. Justice Thomas doesn't participate at all in oral arguments. He is on record as saying that he thinks it is nothing but theater, and could be done away with completely. The case is in the briefs, not the orals. (I should probably restate that, but it's accurate.) I think he missed a case or two earlier this term, and still will participate in them, because the oral arguments are really superfluous.
Now, that still doesn't answer the question of whether or not Ginsberg is healthy enough to actually go through the briefs. I kind of doubt it. I know what chemo does to the brain. Most chemotherapy fogs the brain badly for a while. I know it was really frustrating to my wife, that she couldn't concentrate enough to read a book for several days after chemo treatments.