Greta

Greta is a very friendly ghoul who works at Carol's Place in Underworld. Every once in a while she'll head outside to the Museum of History lobby area to smoke a cigarette. You can loot her body for 10mm bullets, but not the 10mm pistol that she clearly keeps holstered.

Unmarked quest: Hired Help
In exchange for Charon's contract, Ahzrukhal wants Greta dead. You can choose to fulfil his wish or simply buy the contract from him.

Trivia

 * Greta is possibly Carol's partner.
 * Greta is jealous of Carol's relationship to Gob, as Carol states that he is like a "son" to her, though not biologically, as "ghouls don't work that way."
 * Greta takes a smoke break outside the entrance to Underworld (under the skull) between 9 and 11pm. (This is usually the best time to kill her.)

Appearances
appears only in Fallout 3.