In the final scene, just before Alexandra leaves Regina, in the shot when Regina climbs the stairs, and asks Zan if she would "like to sleep in her room tonight", we see a chair in the background (which earlier in the scene, Regina had sat in). The chair seat is empty. Two shots later, when Alexandra collects her hat and coat to leave, they have suddenly appeared on the chair.
When Regina returns home to find Horace in her part of the house, she clearly takes her left glove off before walking towards the staircase. Seconds later, after Horace tells her about the investment in the cotton mill, she turns around at the bottom of the staircase and takes her left glove off again.
On the night before Alexandria leaves for Baltimore when she leans over the railing after Aunt Birdie is slapped: In the wide shot her right hand is about 20 inches from the column, then in the close-up her hand is just inches from the column.