Gee, I've never heard of this in Maltese
or Poodles but I know a breed like a Pug can have elongated soft palates and collapsing tracheas. Does anything ever come out her nose, even a little, like food or water? I ask this because she may have (even a hairline) cleft palate.
Has she been to the Vet or due to go in soon for shots maybe? I would mention this to the Vet and have him/her give the puppy a thorough examination.
Wish I could be of more help.