|Profession|| Head of the Willow Household|
|Family|| Clarice Willow, wife|
Desiree Willow, wife
Mar-Beth is one of Clarice Willow's wives in a group marriage. She adopted the last name of her wife, Desiree. She manages the Willow household. Mar-Beth is a member of the Soldiers of the One. ("Rebirth") ("False Labor") ("The Heavens Will Rise")
She meets Lacy Rand when Clarice invites her over for a Saturday lunch, one month after Lacy's best friend, Zoe Graystone, perished in the MAGLEV bombing. At the dinner table, Mar-Beth notices Nestor flirting with Lacy. She is suspicious of Clarice's and Nestor's motives for inviting Lacy to lunch. After Lacy leaves, Mar-Beth and Tanner challenge Clarice about this. Clarice says she invited Lacy to their home in a friendly attempt to help Lacy cope with her grief over Zoe's death. ("Rebirth")
Amanda asks Mar-Beth about her due date and other medical details about her pregnancy. Mar-Beth says she wants no part of that. She wants to have her child at home. She accuses Amanda of challenging their way of doing things. Amanda says that it is just her training as a doctor and she means no offense. Mar-Beth wants Amanda to leave their home. In order to stay so she can keep spying on them for the GDD, Amanda lies, saying that Zoe was unexpected and that she got postpartum depression. Amanda thanks Mar-Beth for allowing her to stay in their home and that she actually envies their family. Moved by Amanda's "confession," Mar-Beth reconsiders and lets Amanda stay.
She gives birth to a son at home surrounded by her family. ("False Labor")
In order to protect Amanda (his confidential informant) and suspecting there is a leak in the department, Jordan Duram feeds false information to Gara Singh that Mar-Beth is his confidential informant in his investigation of the Willow family's connections to the Soldiers of the One and the MAGLEV bombing.
Clarice is enraged when she receives this information. When Mar-Beth is taking her baby for a walk in the park, Clarice stabs and kills her. Olaf and another husband take Mar-Beth's body away. They chop off her head, hands and feet and throw her body in the Theoresos (a body of water), two-hundred klicks from Caprica City. ("Blowback")
Duram tells Amanda about Mar-Beth's death and the circumstances surrounding it. Amanda is stunned by Jordan's revelation, saying an innocent woman was killed, a woman who just had a baby. Jordan counters that Mar-Beth was hardly innocent and that the baby will grow up to be a terrorist just like the rest of the Willow family. ("The Heavens Will Rise")
- See also Sexuality.