Natasha asked Jace in your last post to go look for 'the mole' and look into the Widow. Jace won't be able to find anything on the mole because Kat doesn't actually have one (She was alluding to Katya- her girlfriend whom is very loyal to SHIELD) she was just flaunting her skills to Alex earlier when she said that. If Jace looks for info on Katya then she likely would hide it/stall/delete anything she could find to protect Kat.
Then either Natasha can figure out while waiting that Jacinda is hiding something (via nervous movements, slow typing, etc.)OR she could confront Jace about it right away, before they even get to a computer (she was acting strange, had a date, was concerned about widow being there etc) or Nat could go see Katya and make observations and ask some questions while she waits for Jace to find something.