I think I saw this movie on Netflix in 2014 or 2015 but my viewing history hasn’t been helpful. It’s a period drama (early twentieth century maybe and British?) The main character, a single woman, works for a wealthy woman as her assistant. The wealthy woman’s nephew, an older bachelor, proposes marriage to the main character and she accepts even though she doesn’t really know him. They slowly fall in love (I remember there is a scene where he teaches her how to swim and there is a secret passage that connects their bedrooms in their home. This becomes a big plot point later.) Eventually, she becomes pregnant. The husband has to leave on a trip for a few weeks. At some point, the plot point is introduced that his brother is a bad person who wants to inherit this man’s estate. As soon as the husband leaves, the brother shows up with his wife, a marriage that the family deems as dishonorable. She is Indian I believe. And with them is someone who is introduced as the wife’s mother, also Indian, but it’s sort of unclear whether this is true. The main character welcomes the three of them into the home but it becomes slowly more and more clear that they are trying to poison her and her unborn child so that they can inherit the estate. The husband receives news of the brother’s arrival just in time to make it home before his wife is killed. She is unconscious and eventually wakes up. The movie ends with a short scene showing the two of them in their home years later with two sons.