The ending is exactly as it seems for Maria. Ive read reviews that said he didn't see her. He absolutely did see her. It's just that he looked at her dismissively, just as one might expect for servants, not giving a second glance. (Don't forget he stopped calling too.) He knew. At the end when he's on the steps with David he said, "a woman I was once fond of" to Stephen, the one who told the lie in the first place. I am a Polly Anna. I like happy endings so this just makes me sad.