Hi Antony,
Your parakeet's nose (actually called the "cere") looks normal. It's a female, and it's normal for a female budgie's cere to look a little rough like that. A female's cere will be tan or brown and will sometimes look a little rough. My budgie's cere looks the same way, and I just took her to the vet recently for a checkup. The vet said she is fine.
As long as you don't notice any other problems like her nose running, then I'd say she is fine. Her nose looks normal to me for a female.