According to an article in The New York Times, Whittlesey was modeled after a female unit manager whom series creator Tom Fontana met at a prison in southern New Jersey.
Whittlesey is introduced as the supervisor of the guards in Emerald City, Unit Manager Tim McManus' experimental cell block, first seen when a new group of inmates, including Tobias Beecher and Miguel Alvarez, arrive at Oz.
However, when the two receive flak from their fellow staff members over their relationship, particularly by Mike Healy, she breaks it off with McManus, who despite his reputation for bed-hopping and womanizing reacts poorly.
Eventually, Whittlesey gets some bad news — Oz has made a contract with the Department of Corrections that, as a condition, will no longer allow officers to work overtime, severely impacting her finances.
When a riot breaks out in Em City, Whittlesey is protected from serious harm or rape by Kareem Said and the Muslims, but ultimately taken hostage along with several other COs.
When Miguel Alvarez attempts to patch up two severely injured guards, Whittlesey reveals she used to be a volunteer nurse and offers assistance, which is ignored.
When the SORT team prepares to storm Em City, Whittlesey is lined up with McManus (who traded himself as a hostage for the two critically injured officers) and the other COs with the expectation they will be the first to get shot and killed.
Glynn convinces Case that Whittlesey is the best guard he's ever had, that she is struggling to make enough money, and that punishing her for taking Ross' life is not worth ruining hers.
Schillinger approached Muslim leader Kareem Said, who was handling cases for various prisoners, and asked him to represent him on the conspiracy to commit murder charge.
When the entire prison is put into lockdown amid serious racial tension, Whittlesey fears another riot, and decides to take vacation leave.