Nurofen for babies worked wonders with my son. I'd give him some before bed, then some again when I went to bed. Wouldn't hear a peep out of him all night!

Try a fan in her room, set on medium -(facing the opposite way, so it doesn't blow on her, it will dry her out and give her a sore throat). The noise sometimes helps soothe them, and it's a constant noise. Helped with my kids!