From your description, this little girl might be in distress.
There are a couple conditions associated with female birds that are egg layers or potential egg layers
Egg binding is when an egg doesn’t exit the female bird. Dystocia is the obstruction of oviposition or cloacal function because of the egg in the distal oviduct.
If you even suspect that your hen (female bird) is egg-bound, getting her to a doctor who is experienced with birds, preferably an avian specialist, is necessary right now. You cannot delay!
In the meantime, making sure she stays hydrated is important. If she isn't taking food and water on her own, making sure she gets some plain water with an eyedropper just inside the beak, a drop or two at a time (slowly, not forcefully) may be helpful in keeping the bird alive until medical intervention.
You can try swabbing her vent area with a bit of KY jelly or other lubricant (not Vaseline) – even regular cooking oil is ok in a pinch.
Set her in a shallow pan of warm water (not hot) – this might relax the muscles enough to pass the egg.
Find an avian vet near you http://aav.org/vet-lookup and
http://veccs.org/hospital_directory.php
Another very productive search site is http://www.vetwebdirectory.net/index.php?option=com_mtzcssearch&template=2
These days, with birds growing fast in popularity as in home companions, many DVM’s are quite experienced and able to see and treat many birds. If you have a pet store that sells birds or know of any bird breeders – ask them who they use for their bird care.
Another possible cause of vent pasting would be urate crystallizations which are not uncommon in birds on a largely seed diet.
Further causes would be impaction from eating grit or other non-food items.
In any case, it’s necessary to have a hands on vet evaluation done to get to the bottom of the issue.
What you can do while securing a vet to see your companion is supportive care.
Most birds will need a heat source to maintain body heat while you’re getting their medical treatment lined up or while you’re on your way to see the vet with them.
If perching is or becomes a problem, lower the perch to just a couple inches above the floor of the cage so falling doesn’t injure them. You might also want to remove the perch completely and layer newspapers on the bottom or put a tee shirt there. We use T-shirts because bath towels tend to have looped surfaces that can entangle little toenails.
Putting a heat source into the cage may be necessary since a sick or distressed bird may lose body heat. I prefer a non electric source and use rice socks.
Use a thick, clean sock and fill it ¾ with plain, raw white rice. Knot the end and microwave it for about 1 ½ minutes. Shake it afterwards to distribute the heat and be sure it’s not too hot.
You can layer a thick towel on one side of the cage, secure with clothespins out of the reach of the bird’s beak – then clip a heating pad over the towel and set on low. Check often to be sure it’s not overheating and that the bird isn’t gnawing through. A side attachment like this will allow the bird to move closer or away as needed.
It's a very good thing you noticed this - what a very good caregiver you are.
Certified Avian Specialist
Cert. Avian Specialist; Int. Assoc.Animal Behavior Consult; Pet Ind. Joint Advisory Council; author