K.T.
Ah, the "terrible two's"....she can do so much more than when she was a baby but is still too little to do so much more. This is a phase, which I'm told will pass (we still see it at 5 sometimes). She can be Mama's little helper (dusting, getting baby supplies for you). She can be Big Sister, Protector of Baby Brother (she could even wear a cape for that role). And of course, she can still be your Little Girl, worthy of hugs and snuggles during your time together.
Having said that, it still won't prevent the whines. You can tell her that you can't hear her when she whines - she can ask in her regular voice and then you'll listen. She is old enough to start hearing that whining doesn't get you far.
As for her paci, we had to reason with our son for quite some time before he was willing to give it up. As she gets more and more engaged in other activities (coloring, puzzles and whatnot), she'll be less inclined to need her paci. Having a younger sibling may make it even harder if he's using one, though. Good luck and keep encouraging her to celebrate her independent toddlerness.