My wife absolutely hates the character and she pointed out why the other night when the episodes were on...
When they're first attacked by the Borg and Shelby comes forward and starts ordering Data to remodulate the phasers, once they break free she has this smug ass look on her face that gives you the impression that she thinks she's the only one who knows anything.
I personally didn't find the character professional or sexy. I thought it was very unprofessional for her to be trying to push for the XO job while Riker was still there and going over Riker's head when he didn't agree with her plan to separate the saucer.
She was an arrogant junior officer who was use to getting her way because she worked for an admiral back at Starfleet.