It appears that we are going to have some house guests for the next few months.
Mama picked a sheltered spot on our back porch that's protected from both of the common wind directions around here. The concrete block pillar also ensures that cats and local creatures that like eggs or baby birds aren't going to be able to climb up.
Given that she's on the nest almost all the time, I'm fairly certain there are eggs in there, though I haven't gone up to check. Hopefully I'll have some baby bird pictures next month!