Even my old programme won't allow me to make people have children before they are 10 or so.
All I can suppose is that this is willful ignorance.
Isabel has son John, before she is even conceived. It's a miracle - except of course there never have been any.
Whoever is in charge of this please de-link these people.
Obviously everyone had two parents, but the default position in any serious form of genealogy is unknown.
No matter how much you desperately want to know.