Come on bombs, now your in the conjecture club. Of course a promise can be supported by consideration. Most contracts are promises supported by consideration! But as the great lawyer that you are, you should also see the Defense argument, and not the obvious Bi lateral K argument, right? I hope you do or else you will be surprised many times in your career.
Your assertion that 'coming over' was part of the bargain is completely ludicrous. Coming over is merely a suggested time and manner of performance. What if Jane had said she would 'bring over a check'...is there no K if she pays in cash?
That's all I have to say about this. You have no idea what you are talking about. Sorry. I suggest you pick up Calamari and Perillo on Contracts, and read the chapter on mutal assent very carefully.