Sneezing and running nose are the symptoms of avian cold. You should show your chicken to an Avian expert/doctor for medication. Prevention is also a good option. Keep the chicken away from the dust.

 I read that avian flu (if that's what she's got) can be cured with 'Star Anise' a spice you can get from any supermarket and also sauerkraut. These don't have to be used in conjunction with each other, but I put them both out for my chicken who was sneezing and looking 'a bit down' and now she's not sneezing and looking very happy again