Thread:EvilDragonLord/@comment-5503727-20170604113958/@comment-26240689-20170604193512

The raws have her as 実姉, which literally means "biological elder sister". I simplified the expression in English.

And we don't know how old the events in Gowther's gaiden are (but we know they're at least 45+ years old because of Nadja's age), so we don't know the precise answer to the first question. Perhaps a couple of years at least?