Description of actual hermaphrodite picks up at about 7:30 (link 1) and finishes in part 3 (link 2):
Old riddle: a woman has a baby, then a few minutes later has another, but the children are NOT twins. How is this possible?
The woman had another child, making them all triplets.
I wish I could find whether Karen Keegan was born a twin. I.e. IIRC there are two situations that produce twins: 1) two eggs are present and are simultaneously fertilized, and fraternal twins are produced, and 2) a single egg is fertilized and later splits, giving identical twins with identical DNA.
It would make sense to me, in Karen’s case, if she were originally one of two fertilized eggs. Then, the other egg split and if the rest of the pregnancy had progressed normally, the result was going to be Karen + identical twins, i.e. triplets. But then Karen absorbed one of the idents. That would explain how her babys’ DNA would match that of her brother (of whom she had absorbed an identical set of DNA) “perfectly.”