Responses

I assume in a world with magic, people only want to have heirs that come from powerful people to create more power. Being illegitimate could possibly mean diluting their family's magic and arcane abilities with some random woman who probably doesn't come from a family with high magic or fighting ability because she doesn't have a last name. It's harder to do a background check on her and justify it publicly. They thought their family would've gotten highly judged for it. But now that they've raised Sherina, they don't think like that anymore.
Ok so what exactly is the difference between an illegitimate child and child born to parents who are married power wise like why would she be weaker than her cousin or considered half just cause her parents weren’t married also does marriage fulfill some type of condition that’s allows you to stronger?