The Bible implicitly states that Jesus had brothers and sisters.
I was raised Catholic too and I understand that this statement does not refer to literal siblings. Wouldn't that be a can of worms!
Perhaps more puzzling to me is the strange situation in Genesis where Cain knows his wife - who was never mentioned as being born. If we assume that Adam and Eve had a daughter that wasn't mentioned, that would be Cain's sister - incest. Perhaps God created other people who were never mentioned besides Adam and Eve?
Who was Cain's wife?