Why Do You Ask?
Someone obviously did not study biology or reproductive sciences. There is no way the baby she is carrying is not hers unless she gets pregnant in vitro. It appears that the person who is asking this question is in some sort of trouble and is trying to shift blame to someone else.
Regarding the response, it is a good thing that there are humans out there who understand the fundamentals of reproduction, and it is for this reason that you should hold out some ray of hope.
What Goes Around, Comes Around
There are still people who believe the Earth is flat like a map, and you have the right to your opinion. If you don’t subscribe, someone should get you a globe, because it’s very easy for them to contact us.
In fact, they may be able to reach California before anyone else in the United States. Perhaps a refresher course in world geography would be a wonderful gift for this unfortunate person so that they are aware of the dangers.