Thank you for the release!
A quick correction: while East Asian languages seem to use the same terms for siblings who are not fully related by blood, Western languages do (at least the ones I know, most importantly here, English). Accordingly, Elizabeth Ulrich Grand, who is mentioned to be a member of the royal family by blood and presumably shares the same father as the Emperor, is the Emperor's
half-sister.
I've seen this type of error a lot, so… Basically, the modifiers to brother / sister / sibling go as follows:
- Half-sibling: shares one parent by blood
- Stepsibling: child of a stepparent by a relationship with someone other than one's biological parents
- Sibling-in-law: one's spouse's sibling or one's sibling's spouse (note the hyphens: they're not optional; "-in-law" is a modifier, so don't pluralize it, but the word being modified, so "siblings-in-law")
- Adoptive sibling: sibling by formal adoption
- Foster sibling: sibling by informal adoption