Wouldn't want the following comment to interfere with your thoughts in any way since I love this series as much as anything I've ever read and I've read a lot in my 70 plus years. The series began with Jessica and Nathan having as close an encounter as can happen. It hasn't been touched upon again although there is a strong relationship between Jessica, Cameron, Vlad, and Nathan and all of them cross the readers mind as young, strong, and attractive and they are in constant close contact. Even Captain Kirk had his relationships and at their age and the continuous stress they are all under, a little romance might be a good stress relief for them and the readers. I've read all releases to date and anxiously await the next.
I have read all the books in this series... twice. except for Episode 2 of Part 2 which has just been released. I've read a ton of sic-fi. This series is the absolute best. Having said that, I 2nd the above sentiment. I'm not a writer so I don't know all the reasons why Nathan and Jessica are not together romantically. At this point they are not bound by the constraints of the EDF or the Alliance. Hoping you will bring them together.
Regardless Ryk,... you rock!