Hi,
Is this a single bird or does she have a mate? If the bird is single, she should not have anything to use as a nest. Generally it is best to just discard the eggs and make some changes to discourage egg laying, which I will include below.
If this is a breeding pair, usually one parent sits all day and the other sits all night. It is normal for the sitting bird to hold their poop until they leave the nest box, and the poop is large, messy and can have a strong odor. Without seeing the poop, I can’t say if what she is doing is normal. However, seed is not an adequate diet for an egg laying bird – or even for a pet bird. Both parents should be eating a nutritionally balanced diet like pellets, along with leafy greens, chopped veggies, some fruit and while laying eggs, an egg food. This can be a commercial dry egg food or you can cook an egg with the shell washed, crushed and cooked with the egg. It is not healthy for a hen to lay eggs often. If single, again you need to stop the egg laying either with changes or hormone treatments by a vet. For a pair, the nest box should be remove between every clutch, whether the eggs hatch or not, and the pair rested for 6 months. A pair should be limited to two clutches per year. If you are concerned with her droppings and her health, I would go ahead and take her to an Avian Vet.
Keep in mind that to lay eggs, she needs longer daylight, warmer weather, abundant food, and a quiet, private environment. The goal is to reverse these conditions.
Limit her light to 8-10 hours by covering the cage early each evening
Do not give her anything to use as a nest – no bird huts or tents, no box, bowl, etc. If she decides to sit in a food bowl, remove it and replace with smaller cups.
Do not give her anything to shred such as paper or cardboard.
Rearrange the toys in the cage frequently.
Move the cage to a different place in the room. Move the cage about once a week, or whenever she shows signs of nesting – settling on the cage floor for example. This disrupts her idea of having a stable place to lay eggs and raise chicks.
If you feed a lot of fresh foods, stop offering any for a couple of weeks, and then only offer them in small amounts about 2 or 3 times a week. You can resume normal feeding later when the birds aren’t being hormonal.
If she is let out of the cage, do not let her get in any dark cozy places and don’t give her free roam.
When you handle her, limit any petting to only the head and neck – do not pet a bird on the body. Only a bonded mate is allowed to groom the body. We can’t be a mate, so touching the body is off limits.
If there is no metal floor grate, then do not use any bedding or paper in the cage tray – leave it bare and clean it daily.
If these changes do not work, you need to talk to your vet about hormone treatment for her.
Thank you for asking Lafeber,
Brenda