Violence perpetrated by people they know. But you're right, it's not about domestic violence enacted by a husband to his wife specifically. I also don't know if these figures take into account domestic violence present in gay LGBTI relationships.That report says 31 women had been killed by violence (including but not limited to domestic violence) in calendar year 2015 to 13 April.
Haven't seen anything to suggest domestic violence kills two women per week.