It's perfectly normal. After a molt, the new feathers grow in enclosed in a feather sheath to protect them. The reaon you're only seeing them on her head is she can preen the feather sheath off herself everywhere else. Scratching her head or gently pulling them off if they come easily is good.

Karen
Chico (conure) and Pippin (budgie)
WI

Ok thank you very much!! I wasn't quite sure and everywhere I went on the internet couldn't tell me anything! I will continune what I am doing with a sure mind now!!

Meghan
Taya (Teil)

You can pinch them between your finger nails to break them up then gently rub and pick them to get them off. Most of them will eventually come off on there own but they can be an annoyance to the birds and in the wild they would preen eachother to remove them. By doing this it will also help you bond with your bird but don't be surprised if your birds starts to preen your hair as well. The best way to see how to remove them is to wach your bird work at the ones he can rach then do the same thing. You will see these around the same time each year as the birds moults and grows new feathers. Just be sure not to pull to hard on the feathers because you could accidently pull the whole feather out.