Here are some notes about a quite confusing thing with a good selection of my characters. Taithin Eston, or to give his full name: Taithin Rafaelatan-Arlyne Eston, has three surnames. It’s not uncommon in the city of Lufas, where he came from. Even Georgina Blanc from The Bar Mage of the Golden Sea would know about this.
As you probably can work out that Taithin is his given name, and is the only name that he didn’t inherit. He is a chosen member of the Vedran house of Eston, for unspecified reasons, so he is allowed to use this as surname. Most people that belong to a Vedran house choose to use it over their other name unless they’ve got reasons to use their other names.
In the case of Tathin, he inherited the double barrelled name from his human mother: Rafaela Arlyne. As the only known parent of Taithin, Miss Arlyne passed down her own family name to her son. However most Vedrans will also inherit their Mothers given name, so Rafaela has a -tan suffix added. The -tan Suffix is in effect to mean “child of”.
If elven princess Acacia Latione to introduced herself as a Vedran, she would say: “Princess Acacia Lilytan Latione.” Acacia’s mother is Queen Lily Iota-Latione, Iota was her maiden name, and she choose to add it her husbands surname as tradition. (Acacia herself would be asked to do the same upon her marriage.)
David Eston and Xochiquetzal Keyia-Eston have different reasons for their surname being used. Due to trouble of speaking her given name, most people just call Keiya by her surname, subsequently she chose to add it to her husbands name. Her husband, David introduced himself as David Eston to then Princess Lily Iota (Later Queen Lily Iota-Latione). Due to his good service, his name was brought up and it became very common, to the point only a few people he worked with knew his original Surname.
Some House members who wish to not direct attention to their house or those who do belong to a house use their Mothers name, and omit the house name. Non-Vedrans usually get more leyway.
As For Sammy in the Image above? During the time where that image is set, she would go by Samantha Solanaea Eston. As she spend most of her childhood as Samantha Solanaea, until she was 17, where an indecent left her and her sister asking help from the Eston House. In exchange for working for the Eston House she could get fed. Later on… Well, Spoilers, I am not going to give away a later book yet.