I could be wrong, but I believe that Pam just learned of the fiber match at the Sundance Film Festival. Shortly before the premiere, she and her sister were crying and hugging and someone asked why they were so happy. That's when Pam's sister inadvertently blurted out the testing results. The information was overheard by others who were present, and it is now "out there" so to speak.
IIRC, I have mentioned before that, at the time of the release of the WMFree, there was still material being tested by Bode. It included animal hairs and fibers. I had always assumed that they were retesting the fibers from the trial in order to eliminate the clothing items from the defendants' homes as the sources. They could have done that, too. However, what is now obvious is that the knife collection of Terry Hobbs was examined.
A fiber was found in a hinge of one of those knives. (This was reported, IIRC, back in 2010 shortly after the ASSC ruling.) However, the State fought to prevent the defense from testing additional items, finally agreeing to the testing since the defense was paying. Obviously, this testing, later ordered by Judge Laser, was completed and the results are being made public or will be shortly.
It makes sense to me that the first people told were the family members. What I don't know is whether or not these results were included in the information sent to Ellington on January 19th. Hopefully, Ellington will "find" the packet sent by the defense and make its contents public soon.