I believe she is between the age of 14-17 years old. Her color is black in the winter and very faded bay in the summer. Her left hind's coronet band is half white with a black stop in the middle of the white and she has a white stripe on her face. Here are some photos:
I'm almost positive the numbers are 13710, although I think it could be 13740. I have no idea what the letter is. According to the chart, the letter could only be A, X, Y, or Z (correct?).
Anyway, I'm having trouble finding her. She would have been bred in Texas.
Any help you can give me would be great!
Thanks in advance!