Breastmilk follows a mother daughter duo as they consider the reality that Dana isn't Kat's biological mother.
| Actor | Role |
|---|---|
 Adina AaronNot listed | Not listed |
 Elizabeth DennehyNot listed | Not listed |
| SSela Aaron2014 Kat | 2014 Kat |
| SSage Mohammadi2005 Kat | 2005 Kat |
| MMatt GallagherKat's Dad | Kat's Dad |
| MMeg GallagherPrincipal | Principal |
| DDaniel GlassmanWaiter | Waiter |
| JJulia SorkinNurse | Nurse |
| KKristina BrukeBreastfeeding Mother | Breastfeeding Mother |
| BBeth EisenNot listed | Not listed |
| JJessica ChiaNot listed | Not listed |
| KKelsey KentNot listed | Not listed |
| EElizabeth JohnsonNot listed | Not listed |
| EEllen GoldblattNot listed | Not listed |
| CCole SisserNot listed | Not listed |
| JJocelyn WaddellNot listed | Not listed |
| AAbbey EklundNot listed | Not listed |
| EEsme GoldmanNot listed | Not listed |