It makes sense that Miss Hawking had something to do with Widmore finding the island, or at the very least Widmore used the Lamp Post station. My line of thinking into how the Lamp Post works is sort of a combination of Science and "Magic". Like, somehow the station can detect when the island is about to move (magic) and it is transferred somehow to the devices in the station (science) that allow the people there to go and find the island. Soooooooooooo, anyway...
I always thought that the Lamp Post could detect that Locke was about to turn the FDW, and that is how it was able to predict the location of the event window that allowed access to the island. Now Locke turning the FDW sent the island through time to 1974, and that was the event window. With the S5 Finale, Juliette blowing up the bomb sent the island through time to 2007 and that opened another event window. Yet again, somehow the Lamp Post was able to detect that the island was about to shift through time, and predicted the event window, so either Miss Hawking was there and told Widmore, or Widmore was there and just used the info to his own advantage.
Am I stating the blatantly obvious here??