My girlfriend is trying to find a story she once read (in 2004, when the book was not new). If anyone can help me earn a few relationship-points it would be greatly appreciated.
The story is set some time near the end of the 1800s, probably in the USA. The main character is a 15-year-old female only child (possibly named Ophelia?) who has gone on a holiday to the beach with her parents (her family has at least some money, but may not have been particularly rich). The beach has (some) segregated bathing hours, since there is a scene where the girl is walking on the beach with her father during the men's bathing time (which gets questioned). While there, she has an affair with a doctor who is already married with children (who may be a family friend or otherwise known to her parents). The two are caught in the act (possibly by the man's child?), leading to the expected scandal. The doctor's marriage is effectively ended by this, although he may or may not actually get divorced immediately.
In the aftermath, it is discovered that the girl is pregnant. While giving birth she is given laudanum (or some form of drug) and when she comes round the baby boy has already been spirited away by her parents against her wishes. She is then sent away to boarding-school for a few years, but this is skimmed over briefly. Her relationship with her parents is effectively over, due to them stealing her baby.
When she leaves the school at around 18-19 she goes looking for her child, and finds him with a couple who are not native english speakers (possibly French or French-Canadian). She takes the issue to court, trying to get custody, and wins her case but chooses to leave the child with the foster parents when she sees that he is too young to understand what is happening and doesn't want to leave his home (the child hasn't been told that she is his mother). The doctor has resurfaced and is involved in the court case, since he had been the one to find the foster parents three years ago.
The story ends with the main character and the doctor reunited, one or both of the foster parents ill/dying, and the child clearly about to be returned to her (but the story ends before that happens).