Agreed on getting her to a vet ASAP-- also, is she only eating seeds and spray millet, because that is not healthy for her liver etc. Are you feeding pellets or chop in addition to the seeds? Birds aren't meant to eat only seeds and when they do, their diet is lacking in nutrients and much too high in fat.
Do you know all about metal toxicity in birds? This can sometimes result in reddish droppings. Anything metal that she comes in contact with should be stainless...Zinc, brass, copper, tin, galvanized metals, lead etc are all very bad. Cages, toys, jewelry, household items etc= all possible risks for your bird.
Certain healthy foods can tint their poop and make it look more red than normal as well. Raspberries, blackberries and watermelon all alter my bird's poop color significantly.
Make sure you are not giving any bad foods to her (salt, excess sugar, preservatives, onion, garlic, leeks, chives, high-fat foods, avocado (due to toxin), chocolate, alcohol, caffeine, coffee of any kind due to a chemical found even in decaf, tomatoes, certain herbs, rhubarb, artificial sweeteners, raw honey, alcohol etc...birds are also lactose intolerant).
Make sure that you have no dark spaces or huts in the cage--- these can trigger nesting behavior and lead to egg-binding which can kill a bird. You want to make sure your bird is not hormonally triggered as much as possible to prevent egg-formation (even in single birds). Does your bird appear to be straining at all? You might just Google egg-binding so that you know what to look for.
Have you checked all of her feathers and the surface of her skin to see if she may have broken a blood feather or scratched herself somehow? I guess I'm asking if you are certain it came from her urine. Did you see it come out of her?
