I've just played it back and Jenna was already miffed about Scoop leaving and not Janice as Janice hasn't partaken in any tasks. There were a few round the table at the time. Later, Natasha is at the sink when Jenna mentions nominations approaching, and that she has a couple. She then mouths to Farrah, 'probably Janice'.
Natasha may remember the conversation but its unclear if she saw or heard what Jenna whispered.
Can you imagine the uproar had it been Janice talking about her?