Can a adopted sister marry her brother?

Answer 1

No, you cannot. An adopted child is considered a child of the parents in every legal sense. And you cannot marry a sibling. Actually, apparently you can. Look at actors, Linday and Bryan Price. Their parents were brother and sister by adoption. Their mom, adopted from Korea by the Price family married her brother. So, apparently, yes it is possible, under what circumstances and what they had to do to accomplish this I do not know.

Answer 2

If you mean, "Could a brother impregnate his sister", the answer is yes. Just like any other male/female pairing. A brother could also impregnate his mother, producing a sister.

Incest is taboo, but the actual increase in the likelihood of birth defects is only like an additional 2%. It's still creepy to bone your sister, though.

Answer 3

Yes, an adopted sister can marry her "brother" because they are not biologically related.