I love 1897! It's my favorite storyline as I've already said earlier.
I think that Quentin is the youngest. I even came up with a storyline about why he is so spoiled. His name means the fith born. (This was before the sloppy 1840 storyline when they had another Quentin and had the 1897 Quentin be his namesake.) Anyway back to my theory. Edward is the oldest, Judith is the second child, Carl is the third child, then their mother lost a child, so when their fifth child is born his parents dote on him not only becausehe's the youngest but because of the child they lost, and they name him Quentin,so everyone will always remember the child who is no longer with them.
I also remember when [spoiler]Quentin was in Petofi's body,[/spoiler]he told Judith that he could "see" things about people, and told her about Quentin hiding behind a chair and witnessing their nanny punishing her for something. This would imply that Judith isn't that much older than Quentin even though I thought she was until I saw this scene.
Misa