S.K.
You might have to try a few nights of ignoring her. Pick her up and put her back to bed, no comforting, no changing her diaper etc. explaing to her once that night time is for sleeping tell her you love her and leave her in her room and put a gate up in her doorway. It's going to be hard and no one will sleep for a while. But it's better not to draw any attention to her or give her any comforting during that time. Little ones can sense the new baby and this is her way of getting extra attention. Make sure that she gets lots of hugs and kisses during the day time. And remind her every night during story time that night time is for sleeping. Maybe you could offer to take her somewehre special, just her and mommy or daddy or give her a special prize for staying in her bed. Temporary tattoos are big in our house and so is McDonalds so we always break those out. Good Luck, I know how hard it is with a newborn and a 2 year old! We're having our own set of issues and it's great to get advice from other moms :)