From Al.com:
Sonequa Martin-Green, a 2007 alumna of the University of Alabama’s Theatre and Dance department, now has a part on AMC’s zombie hit, “The Walking Dead.”
Green began her role on the Dec. 2 episode “Made to Suffer”, as Sasha, Tyreese’s sister. Sasha is one member of a small group of zombie survivors that includes her brother as well as Allen, Ben and Donna.