Yes .. but Dietrich loses his memories after he escapes. So Charlotte is the only one who remembers. Noah also ends up disappearing because the curse on the mansion was broken.
The story still continues for like 100 chapters after though, and a lot of people say the story deteriorated after that point.
SPOILER
so I looked into the spoilers after seeing your comment. And you were kinda right but a bunch of other stuff also happened. The ending is technically not a sad ending, as Charlotte and Dietrich do end up together, it's just an open ending since you don't know wether or not he still has his memories. And yes Noah does end up disappearing, but after he disappears and charlotte leaves the mansion she becomes pregnant with another child, and while this could very much not be noah, because of other circumstances she would like to imagine it's him.
Looked up the novel for spoilers...
Wahhhhhhhhh it's sad... The story is sad and the ending is also sad... They don't get a happy ending and Dietrich doesn't remember her. On top of that the Dietrich she meets outside is different.
On top of that. Noah is her child, but she doesn't remember him. He ends up disappearing to save his mom... I might drop this it's very depressing