How old is she, and does she lay eggs? Is she passing some normal material in her droppings? The white material is probably urates/uric acid or kidney waste. It can dribble out if there is some vent damage or vent gleet, a fungal infection. Vent gleet causes raw sore skin and missing feathers around the vent, and a bad odor. Could she be egg bound? Do you have any calcium tablets or Tums that could be given into her beak to swallow in case of a stuck egg? How does her crop feel? Has she been eating? A swollen lower belly could be water belly/ascites. Is it squishy or firm?