Have you been able to find the source of the bleeding - inside her mouth or the beak itself? Trauma and vitamin K deficiency are the two main considerations. A bleeding tail is likely to be due to pin peathers (new feathers that still contain a blood vessel) that have been broken through the vessel. A vitamin supplement such as Oasis brand contains vitamin K and can be added to your parakeet's drinking water.
Nutritional imbalances are a common problem in our pet birds. What has her diet consisted of, please? Seeds should compose less than 20% of her diet. A diet of mainly seed and nuts has excessive fat, carbohydrates, and phosphorus; marginal protein; adequate vitamin E, and are deficient in amino acids, calcium, available phosphorus, sodium, manganese, zinc, iron, vitamins A, D3 (necessary for efficient absorption of calcium), K, and B12, riboflavin, pantothenic acid, choline, and available niacin. Ideally, a balanced pelleted diet such as can be found here: www.harrisonsbirdfoods.com or here: www.lafeber.com/pet-birds should be fed as well as hard boiled egg yolk, pancakes and cornbread, the tops of fresh greens, dairy products such as yogurt and cheese, fresh fruits such as apples, pears, melon, kiwi, and berries, vegetables such as broccoli, carrots, beets, asparagus, cabbage, sweet potato, and squash, and even tiny pieces of meat.
Please respond with further questions or concerns if you wish.