After looking up NC's statutes on spousal privileges, I found these two links. That's if their marriage is legit if AY's wasn't. I don't see how how either AY's or AB's was legit.
NC statute
§ 8‑57.1. Husband‑wife privilege waived in child abuse.
Notwithstanding the provisions of G.S. 8‑56 and G.S. 8‑57, the husband‑wife privilege shall not be ground for excluding evidence regarding the abuse or neglect of a child under the age of 16 years or regarding an illness of or injuries to such child or the cause thereof in any judicial proceeding related to a report pursuant to the Child Abuse Reporting Law, Article 3 of Chapter 7B of the General Statutes of North Carolina. (1971, c. 710, s. 3; 1998‑202, s. 13(d).)
http://www.ncga.state.nc.us/EnactedLegislation/Statutes/HTML/BySection/Chapter_8/GS_8-57.1.html
Definitions of Child Abuse and Neglect: Summary of State Laws
Child abuse and neglect are defined by Federal and State laws. The Federal Child Abuse Prevention and Treatment Act (CAPTA) provides minimum standards that States must incorporate in their statutory definitions of child abuse and neglect. The CAPTA definition of "child abuse and neglect," at a minimum, refers to:
"Any recent act or failure to act on the part of a parent or caretaker, which results in death, serious physical or emotional harm, sexual abuse, or exploitation, or an act or failure to act which presents an imminent risk of serious harm
http://www.childwelfare.gov/systemwide/laws_policies/statutes/define.cfm