The bottom lines here are not all that hard to pinpoint.
1) Igarashi-sama has gone on record stating that he considers the gameplay first, the story second.
2) OoE was a good outlet for him to try out the first female protagonist in his timeline and he felt a whole new character unrelated to any past bloodlines was the way to go.
3) Albus implies through his memories that he and Shanoa are not in fact related by blood but still sees himself as her brother seeing as how he is really all that she has.
4) Overall, OoE's plot turned out to be one of the most pointless and unnecessary CV outings to date, adding nothing of relevance to the mix and leaving only more plot holes and questions for the fans to mull over.
And finally 5) I think we can all agree that any dialogue from Judgment can't really be taken even remotely serious.
That being said, I got nothing to contribute to the actual topic at hand. . . . . . . . . . . . . . .
Ohh-kay fine. You ask me, Shanoa is related to Hector and/or Isaac. They gave up their surnames, she has none. In fact neither do Barlowe or Albus. Do the math.