Born in 2051, Carol was alive for the events of the Great War of 2077. Living in Washington DC, Carol and her father had sought safety in a fallout shelter within the city proper, after the Chinese first strike destroyed the West Coast. Carol had barely entered the shelter, and was turning back to find her father who had stopped to help another family, when the thermal pulse from a nuclear explosion flash-vaporized him and knocked her unconscious. Hours later, Carol awoke and ran back to hopefully find him, but instead she only found his shadow permanently burned into a wall. Other survivors then took Carol back into the shelter.
Carol did not stay in the shelter long, however. After the nuclear barrages ended, Carol ventured out into the city to seek a place to survive. Much of the city had either been reduced to rubble or was still aflame following the nuclear bombardment, but Carol was able to find safety in the relatively-undamaged Museum of American History's "Afterlife" exhibit. Carol has been there ever since.
Over time, more survivors gravitated to the Museum, almost all carrying stories of the lawlessness and chaos of the wasteland. This further convinced Carol to remain in the Museum. However, as time passed, Carol and many of the other survivors began noticing odd physiological changes, with dry, flaking skin being dominant. Although the rate at which the disorder progressed varied from person to person, the end result was ghoulification: the entire population of the Museum had become ghouls. While some had eventually turned mad or even become glowing ones, others, like Carol, just accepted their transformations.
It is unknown if these "mad" ghouls were ferals or if they just went insane from the psychological damage caused by the transformation.
Carol is perhaps the sweetest ghoul you'll ever meet. The fact that she's a hideously deformed ghoul hasn't stopped her from wearing a sundress, smiling pleasantly, or sharing a warm hello with anyone who crosses her path. She always wanted to open a bed and breakfast, and Carol's Place is her dream come true, although everyone has noticed that she's been a bit down lately.
Carol met another ghoul named Greta in the mid-2210s, and treats her like a daughter. For over sixty years, the two have jointly run Carol's Place, with Carol handling sleeping arrangements and Greta serving food.
At an unspecified time prior to the emergence of the Lone Wanderer from Vault 101, Carol befriended and "adopted" a ghoul named Gob. This caused a small rift between her and Greta, which Carol would later ascribe to jealousy. Whether or not that was correct, Gob later moved out and carried on the family tradition as a barkeep in Megaton, and the relationship between Carol and Greta stabilized, though Carol often worries about Gob's well-being.
Although Carol is hesitant to talk about her experiences during and since the War, she will tell her story if encouraged.
When talking to Carol, you can ask her about Gob. If you blew up Megaton and tell her that you killed Gob everyone in Underworld (except Doctor Barrows, his assistant, and sometimes Tulip and Willow) becomes hostile towards you (including Charon, even if he is your follower). If you didn't blow up Megaton, but killed Gob, only Carol will become hostile to you. Killing her in self defense will not result in any Karma loss.
If you mention you think Gob is a slave, Carol will say she's sad for him, but is glad to know he's safe. She also asks you to take a message to him.
If you just tell her that Gob is dead, she will become very sad and start talking about how she was "thinking about Gob" every time you chat with her.
Carol claims that she was "a little girl" when the bombs fell, and her story of "looking up" at her father seems to support this. Therefore, her birth date of 2051 (which would make her 25 at the youngest in 2077) must be a mistaken memory. However, she could mean relatively as she is over 200 years old.