Yes, she did, which is why I mentioned it -- it was in the ep where they found the map and the X on the bottle ("X marks the spot" is another classic) and Neal had to "meet" her at Grand Central Station. At the station, there was an X on a strut holding up the overpass, and behind it, a note that could be read with the mad-magazine-folding-trick.

In a later episode, Neal gets another note from her, and folds it all kinds of different ways trying to find the secret message.