Her last job didn't go so well in the delta quadrant....
I heard she got to admiral by Hacking Picards account at Starfleet by transferring all promotions to picard to her file.
She did this before she got stranded and this is why in the last TNG she was an Admiral and picard was still captain...
I guess Starfleet has an Affirmative Action Program even in the year 2370. Picard got screwed for that promotion. :)
Picard did not want the promotion to Admiral... Not his thing...
But who knows, if Paramount does a movie post nemesis, you may see or hear mentioned an Admiral Picard.
Some of the Trek novels hint at such a thing, but these are not official canon.
she got to admiral by Hacking Picards account at Starfleet