What a beautiful family!!
This reminds me of my friend's story. Purchased a mare from a "feedlot" (CBER - 2005), had her shipped to OH. She arrived skinny. Early the following year, my friend found out the mare was indeed in foal and she delivered a beautiful filly (now almost 6). Sadly, the mare passed from complications 5 weeks after foaling.
It is amazing that your mare could retain the pregnancy as well and that she gave you such a beautiful filly.
My friend was able to get in touch with the breeder who gave her all the certificates to have her filly registered (TB) although the mare was culled as barren!!!