Sermons 355 and 356 were delivered by Augustine in 425/426 when it turned out that some clerics of the monastery of Hippo had retained some private property.
It seems that Januarius joined Augustine's community while already a presbyter. We do not hear anything about his wife, presumably dead before he entered the monastery, especially as the children (under age at the time) were sent to other monasteries.
Augustine refers shortly to the case of Januarius in Sermo 356, 2 and 11 (when he repeats that the Church of Hippo forwent any claim to the money of Januarius, leaving it to his children).