My baby keeps putting things in her nose - what should I do?

Keep small toys away. Keep toys small enough to fit inside a toilet paper tube away from the newborn, they are also a choking hazard.
Baby-proof the home. A baby should not have access to things small enough to fit inside the nose, ears, or mouth. Small items will choke a baby.
No small objects. Children are naturally curious and will place objects where they think they fit nicely, be it the nose, ear, mouth, etc. You should not allow your child to play or handle small objects. A good rule is if something fits inside a toilet paper tube, it is not appropriate for a child under 3 years old. You would be amazed what doctors have removed from childrens' ears, noses and other places.
Remove opportunity. Keep all small objects out of her reach until she's older. If she is putting things like carpet fiber in her nose, don't let her be on the carpet until she's older. If you catch her doing it, hold her hand and say "no" in a firm voice and take the object away.