Sarah, along with Rachel, Marv, Hank and Wilf, is a non-player character that may be encountered during Temple Trekking. The challenge involves quickly feeding them before they turn into ghasts. If this happens, the ghasts must be killed.
She can be fed almost any normal cooked food, but in case the player does not have any food, then the nearby snails can be killed and cooked for her to eat.
The longer she is left without food, the more she starts to resemble a ghast before finally turning into one. High level followers will help with this by starting a fire.
