I'm a bit confused on this one. If this is tied into ancestry being considered matrilineal, we don't actually know her mother's last name. We know the last name she had after being taken in by her foster parents, but that name could come from the foster father (Marvel wikia claims Mrs. Dane is Arnold's sister).
I'm not sure how much stock I can put into that site given the line below.
"She's not religious therefore she's more vulnerable to teh evils" is a pretty weird argument. Maybe that kind of idea would make sense if this was Diablo, but not so much here.In fact, her lack of strong religious convictions may help explain why she, more than any other member of the X-Men, has so frequently been controlled by other people and influenced into becoming a traitor to the X-Men or a villain.