She will tell the Vault Dweller that there is a water chip in Necropolis. Also, if the Vault Dweller is running out of time to retrieve the water chip, for 2000 caps she will commission a caravan of water merchants to deliver water to Vault 13, which will extend the time limit of the quest by 100 days. The Vault Dweller with a sufficient Barter skill can haggle her down to 1000 caps or even to 500.
After handing in the water chip to the Overseer, the player can commission a second round of water caravans. Doing so will award the player with 1000 XP, unmark the Find the Water Chip quest and attach a 'days remaining' note to the Vault Dweller's Pip-Boy 2000. This will effectively reset the results of the Find the Water Chip quest; the citizens of Vault 13 will act as if the water chip has not been delivered and after the time limit expires the quest will end in failure. [verified]