She’s eating normal and drinking, no off behaviour. Still feeding her chicks too. The lump is soft and you can move it around. And yeah the feathers are still growing on it. I took a look at it and there’s no inflammation on the surface area of the lump. It just kinda developed out of nowhere. Also droppings are normal!Oh! that sure doesn't look normal... Is the lump hard or soft? Are feathers still growing on it? Is the bird acting normal? How are its droppings?
Best to take the bird to the vet and make sure it's not some type of cancer.