That may be the case (I never watched BSG), but I'm not sure if that precludes her from writing a story in what is ultimately a very different setting.
I'd also note that sometimes plots occur more than once in literature and entertainment by mere chance. Shocking, I know!
Edit: having looked up the Caprica plot on Wikipedia, really, they have nothing in common.
I didn't want to sound dismissive or snarky in any way. If I did, then I apologize. I was just providing an example of other story based on "industrialised, polytheistic society with monotheistic terrorism" :).
I hope strongly that your friend will publish her novel successfully; I'm eager to read it.
BTW. If you never watched BSG, I recommend it strongly (the new one). It's a masterpiece.
Add to this a side plot about creating sentient machines and you basically summed up the storyline of Caprica, Battlestar Galactica's prequel.