perform the "Move" on her:
Pull it out, look at her in the eyes, and say "Now what are we goin do about this?"
If you can't manage that, I was in a similar situation with a girl who liked to fuck but was kind of scared to suck dick. Over time, being a few weeks to a month or so, I politely mentioned how much I think of blowjobs and what they mean to me, how personal they are, how passionate they can be, how hard they make my cock so I can fuck better...things like that. Don't just make it into a can suck you my dick kind of thing because it feels good. I real blowjob means much much more...an appreciation of manhood and a display of female sexuality...
*now she thrives on sucking dick and can't imagine life without it...she says she does not feel complete unless my hard cock is down her throat...there is a chance my friend. Just take your time with it and don't rush her, make a lot of noises etc to show how good it makes you feel she may get exited to do it more then...