You know, during the Ocean Palace disaster, wasn't there an Enlightened woman who got zapped by the Mammon Machine apart from the Gurus and Janus (I don't remember clearly, maybe I'm just imagining it...)? The Gurus and Janus were all teleported to the eras Crono can explore (600AD, 1000AD, 2300AD, End of Time), except 12000BC (obviously), 1999AD and 65000000BC. It's clear that nobody could have been teleported to 1999AD, since Lavos didn't provoke the Apocalypse yet and it was a normal date. So, perhaps that woman was teleported to Prehistory, and perhaps she was pregnant...
It's quite far-fetched, and I don't even personally believe in this theory (sounds more like a fanfic story), since I think the game would have made it clearer and more explicite if it was true, but I just wanted to say it, just in case.