For a femshep there are at least two opportunities for the dinner date. One is after recruiting Thane. When Kelly says "some women are into bad boys" if you reply with the middle option "he's not my type" or something like that, you should get an opportunity for dinner. The other option should appear after the Collector Ship mission. Ask Kelly for a hug and you should get the option to have dinner.
After I recruited Thane I saved the game before I went to talk to her. Then I did talk to her and she said "some women are into bad boys". I tried both options the "paragon" one, the upper option and the "neutral" one, the middle. Both of them DID NOT led to the dinner opportunity.
I didn't tried the hug option after the Collector Ship mission.
I think the option of dinner did not happened to me because my FemShep was already too engaged with Jacob.
Another detail: I recruited Thane after Collector Ship Mission.