So, I am wondering if anyone might be able to give me some suggestions. I have a character idea; she's my Navigator Asteira Volaris. Asteira is an experiment of her father, Novator Daedalus Volaris, in an effort to create a more aesthetically pleasing Navigator. Through considerable T&E, he finally fabricated a stable speciman whose Navigator powers were decent, and who didn't look like a monster (when you imagine that half of her DNA is his, and the elder Navigator looks like Guild Navigator Edric from Dune Messiah by Scifi Channel, that's a major accomplishment). He efforted to breed in the most stunning, attractive features he could, while working around the Navigator gene's mutative properties, trying to stymie them as much as possible. 20 plus years later, what he got was one of the most breathtaking humans most people will ever see, with the only notable oddities being a penchant to ALWAYS wear elbow-length gloves, and blood like tree sap, rather than blood. Her third eye is concealed behind a small, technical marvel of a circlet, with sensors that can detect the muscle movements, and open an iris to reveal said warp eye when necessary.

Okay, thanks for reading all this crap, now, onto the question. Asteira exists both to try an improve the baseline Navigator, at least on her family, and to serve them in enterprises. She is a skilled diplomat, and a capable business woman of a sort, in addition to being a skilled Navigator, and a Navis Scion, as well. Is there anything I might do/add to increase her Fellowship effectiveness, mechanically? In her block, at lvl.2-3, she has a 51, though Fellowship is tricky for Navigators to raise. Many Traits have something that can be added to make them more effective, and the sultry, social Navigator could possibly benefit from such, but I don't know of one for Fellowship, beyond Unn Fell, which only Slaaneshi servants seem to have. Any ideas would be much approved. Her Fel-based skills are already pretty far along, thanks to Navis Scion, so I'm not sure where else to go. Maybe she already has everything she needs to woo prospective clients, and get work done, I'm not the best judge in this system. She's more a fanfiction story character, at the moment, but could easily be a decent PC in a game, if ever I get to play in one.

I had a statblock here, but the site ate it twice, so you can ask if you care, and otherwise, it stays shorter this way.

A 51 Fel is already fairly impressive, especially if you have the social skills to back it up. I wouldn't try to force it to 'beyond what's normally possible' or the character starts looking like a really offensive example of a fan fic piece.

Your best bet probably lies in gaining Peer and Good Reputation talents as elite advances.  However, realize that getting those talents for one group may exclude others (for example, getting Peer and Good Reputation [Adeptus Arbites] may exclude you from gaining the same talents for the Underworld).

I'm playing a Fellowship-heavy Navigator right now: a sort of Don or Crime-Prince with a network of informants and lackeys all over the ships of our fleet, who is always skimming some Profit off the top. I basically I just sucked it up and paid for a Fellowship increase to get myself to a pretty respectable 46. My GM allowed me to buy Inquiry at Rank 1 and I picked up the right skills. It's worked awesomely so far and I've never had more fun playing a Fellowship-heavy PC.

As HappyDaze said, if you've got a pretty good Fellowship to start, and the right skillset, you should be good to go - the rest is role-playing. If your group is anything like mine, you'll be roleplaying most of the social encounters and possibily getting a few situational bonuses as a result of good RPing.

Oh, and save those Fate points for social situations.

this page isn't what you mean ? 

http://gameroid.blogspot.com/2009/06/lord-of-4ok-rings.html

I'd definitely suggest looking at the Navis Scion from Into the Storm -- it is an Alternative Career Rank for Fellowship based Navigators who represent their houses to others. 

You've already mentioned the Navis Scion alternate rank, and you have a good stat block so far (51 fell is impressive for a navigator). Have you looked into Peer/Good Reputation, other talents like Warrant of Renown (which works per character that buys it afaik and not the whole party) and finally implants like the pheromone generator (social bonus) or other implants like the one that allows you to digest almost anything, handy when dealing with exotic or potentially dangerous foodstuffs at formal meetings.