Get caught by her in their house when she is on the way between either the kitchen and the table, or the table and her sewing room, it's a very small window and you have to let the time cycle by itself and be standing in the right area especially for the sewing room as too close to the table and you'll get caught during dinner. After you get thrown out, sneak upstairs and then wait for 2am on a night when Roderic doesn't go downstairs. Either watch from their bedroom door, or from behind the partition in their room.