Explain Scout use of verbal irony of the Simon Finch's character and what she means to say about her ancestor?

Scout explains old Simon Finch's house, "The internal arrangements of the Finch house were indicative of Simon's guilelessness and the absolute trust with which he regarded his offspring." The irony is that he didn't trust his daughters, "The Daughters' Staircase was in the ground-floor bedroom of their parents, so Simon always knew the hours of his daughters' nocturnal comings and goings." Scout was implying that his daughters were apt to nighttime "adventures" with boys.