Character Analysis
Little Lord Sebastian Sandown is the youngest rich kid on this ship. He's the future Earl of Clovelly, which means he's super upper class and has a title, so while he may be only five years old, he's already having the time of his life. We're not sure what he's up to during the day, but at night he's chomping down on sweets in bed and playing with toys way past his bedtime.
Lord Sandown is most important as Helena's human friend. She's been wanting a human pal for a while, and Sebastian is just the little gent for the role: "Moreover, from this night forth, Louise wasn't the only one with a human. And mine had been born with a title" (11.110). And just like that he's become Helena's favorite.
As we can see in the quote in the previous paragraph, Helena is pretty proud of Sebastian's aristocratic rank. But she also knows that the little guy just wants a friend: "I saw he was lonely. A lonely little human boy who needed company" (11.43). And you know who else needs company? Helena, that's who. It's a win-win situation for these two.