please refer to this topic thread....Gary has the same issue with his finch.
Your finch may have a parasite, Deborha wrote this in regards to an article I had posted on the subject a while back
http://www.finchforum.com/viewtopic.php?f=4&t=18307
"I skimmed the avian medical reference that Cindy has posted previously and all I could find was a paragraph on the following:
Trichomonas
Trichomonas spp. infections are occasionally seen in finches, particularly those housed near infected budgerigars. Clinical symptoms include gagging, neck stretching, regurgitation, respiratory distress, nasal discharge, green diarrhea and emaciation. Di- agnosis is made by identifying the flagellate on a wet smear prepared from a crop wash. At necropsy, caseous material may be seen lining the crop and esophagus, and flagellates may be identified from this material provided that it is fresh."
It is very difficult at times to differentiate regurgitation and vomiting. Both involve bringing up food and expelling it from the beak.
Regurgitation to a mate, person or toy is a normal part of breeding behavior. A bird that is regurgitating or vomiting will make a head-bobbing and neck-stretching type of movement. Food will be brought up and deposited on the bird's toys or mate. Such controlled regurgitation usually does not result in staining of the feathers or the beak.
Bacterial, viral and fungal gastrointestinal causes, obstructions, toxins and liver or kidney problems may also cause regurgitation or vomiting.
Vomiting, on the other hand, is usually a rapid flick of the head, which is often not noticed by pet bird owners. Tell-tale signs of vomiting in birds is the flicking of small pieces of ingesta around the cage and on top of the birds head. Food may become caked on the bird's head giving it a spiky, matted appearance. Vomiting often occurs along with regurgitation and is a serious clinical sign."
Do have Ronex12%, if so double the powder and and dose for 3 to 4 days the give for the remainder for a total of 7 days treatment
Ronex 12% by Morning Bird Products....
""RONEX Extra Strength is a treatment for cankers, giardia and other protozoal infections.
SYMPTOMS OF PROTOZOAL DISEASES:
canker or large yellowish masses in the throat or crop
weight loss
regurgitation
dried saliva around beak
DIRECTIONS FOR USE:
Ronex Extra Strength successfully treats motile protozoa such as Trichomonas, Giardia, Hexamita, and Cochlosoma. Add ½ teaspoon (2.5ml) of RONEX Extra Strength to 2 quarts of clean drinking water and administer for 7 days. Use as bird’s only source of drinking water. For particularly difficult infections, increase dose to 5 times normal for 3 days then continue with normal dose for 4 days. Preventative treatments are recommended to control further protozoal infections. If bird does not improve or condition worsens, consult a veterinarian. Keep container closed before and after use. Store in a cool, dry place. One level teaspoon equals 5 ml."
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Question, is she constantly eating, do you see her more than normal? Are her dropping alright?
Today when i came home i went to the society finches cage. When i got closer - i saw that my hen started "nodding" her head back and forth, as if she was trying to bring something up. What came up was a little slimy blob of half-digested seeds 
i thought she was only regurgitating food to feed one of the males - but then she did this again, started doing the back and forth head motions and regurgitating. This time she shook her head very fast though, so the "stuff" she regurgitated flew around in the cage and onto her. 
Should i do anything until its time to go ? 
i have only seen it happen this one time today. 
