A teenage girl is pregnant via rape. The father of her child (and the rapist) is her cousin. (I'll skip the backstory, but she kept the child because she is so anti-abortion on a personal level that this scenario could not even change her mind.) His mother/her aunt, who keeps this son of hers on a pedestal, does not believe the child is her son's and accuses the girl of getting pregnant by her then-boyfriend. When the child is born, both boys go in for genetic testing--the boyfriend knows it's not his, but he does this more out of proving himself. I know that a man can be proven 100% not the father (thank you daytime television!) but what I want to know is what's the highest percent a person can be proven the father? I think it's 99%, but I may be wrong. Also, this book is set in about 1993; what was the standard for paternity testing? Was DNA testing avaliable? and if it wasn't, what was the most accurate test a person could get?
A woman is the surrogate mother of a child for her friends, a married couple. The egg comes from another woman later revealed in the story, and the sperm is from the husband of the couple who later passes on before the child is born. The surrogate mother (theoretically) has no genetic ties to the child. How would you test who the mother is genetically, say for a legal custody case? Does this go the same way as paternity testing? It's set in the modern day, so DNA paternity(maternity?) testing is avaliable.
If more information is needed on either question, I'll give it gladly; I'm trying to ask without giving away the plot in either one.