Poofy neck/back but no aggression?

[Linearis]

Lately (for the past week or so) my bird's back/neck has been a bit poofy at times but she doesn't seem to be more aggressive than usual, could it be hormones even if there's no outward aggression? The rest of her feathers are normal and it's not all the time, I notice it more when she's sitting still. She's always been relatively gentle, she must be about 8 months now (she's a parrotlet). Everything else seems normal, droppings are normal, she's eating well (well, that never actually seems to change... to put it into perspective, she gained weight while sick before), no weird stuff in her mouth... She is losing more feathers than usual while preening but I haven't noticed her pulling so I'm guessing she's molting, her clipped feathers have been falling out more lately and she can fly again (just 3 clipped feathers on each wing left to lose now).

That's about all I can think of, she's still quite active, climbing all over the place.

 

[Birdbabe]

Birds poof to keep cool or warm, and poof when moulting..it does take alot to moult and grow new feathers. If shes acting normally, then keep an eye on her, and her poo. Only you know her.