Talked to a DNA tech today - turns out no labs in the US (or most places) do relation testing for birds anymore. Supposedly, it's cost-prohibitive (anotherwords they have to charge too much and don't make enough profit off it). There are only 2 labs left that do it. 1 in Canada and 1 in Italy.
I called the one in Canada:
HealthGene
1-877-371-1551
They charge $ 64 USD a sample for relation testing. IIRC, it takes 4 weeks to proccess. Also, they test can only be done with whole blood, not blood cards or feather. So you have to send in vials.
This being both expensive and complex to do - I'm going to try to track down the breeder through Petsmart if I can. Maybe they'll know if the 2 birds were siblings or not.