well, sepulchure was only alteon's former best friend in the AQW canon. in the DF canon, alteon had never even heard of sepulchure when he was first introduced. tomix even confirmed once that DF sepulchure does not share AQW sepulchure's canon, saying "if you want to learn about dragonfable's sepulchure, look in dragonfable!". it's very likely that the whole "lynaria was alteon's wife" thing is exclusive to AQW as well.
I meant the one in AQW, the ones who actually are mortal incarnations of Elementals.
ah. yeah, in that case, you would be right, AQW gravelyn is not sepulchure's adopted daughter. their familial bond is biological.