That could be exactly why she is dropping feathers right now. Trauma. I hope she gets through this and again when she begins to grow back her feathers and is preening good again she is 100%. Speaking of molting here we are almost into Jan and I still have birds finishing up their molt, never have I had birds molt this time of year. Whether what you see is molt or losing feathers from the trauma, once those feathers are replaced she should have good feather quality again.
How is she otherwise? has she fully recovered in other ways she may have been affected by almost drowning?