disable her AV then. doubtful she'll notice, if she does there's gotta be a way to make the little logo pop up in the tray without it actually running. just a dummy app thing.
also what messenger program does she use? if she uses Windows Live I might have a trick you can use. also check this
http://www.demonoid.com/files/details/1846236/19521570/ out, might work for you.