Is it possible to trace back from previous owner to previous owner etc back to breeder? Or is there a gap in her ownership history too?
As someone else suggested maybe put togther all the info you have and photos in an email and send around to breeders and other large stables in the area.
She DOES look like a Portland. Don Toney is a warmblood breeder near Lethbridge, he might be one to touch base with?
You could try posting on some Alberta facebook sites as well, Canadian Warmblood Alberta Chapter might be one place to start, here’s the link: https://www.facebook.com/groups/342578769231887/
Hopefully you can track her background/papers down!
Did the people who gifted her remember anything about her pedigree? Who did they get her from?
It will be very hard to get papers without identifing the horse first.
It seems odd that she is nice enough to breed but she was gifted and pedigree information wasn’t passed on.
Hope you get some info on her 
Get a DNA sample and check her against Portland, Zodiak, Autocrat, Ikoon. It will cost you some money, but will be worth it. In the meantime, contact Don Toney, He may be able to help you.
So I’ve sent some emails to some breeders in the area. Fingers crossed someone recognizes her!
Hope you are successful in finding out her identity. The Arab registry just in the last couple of weeks has started to offer DNA searches without specific parentage. I am not sure who does the CLRC testing but was told that Maxam in Guelph may be able to do it as well. And if you are totally unable to find out who she is for approvals, you might consider crossing her with a good Arabian stallion to create a quality registered half-Arabian sporthorse who will be eligible for breed competition.
The Jockey Club also does DNA searches without known parentage, so it’s certainly worth asking potential registries if they can run her DNA against the database. For it to work, she would have to be young enough to have had DNA collected when she was registered.
So here’s the update- Unfortunately Don Toney doesn’t recognize her, but has given me the lead onto another breeder from the area who might be able to help. Guess we will see where that takes me!
OP - just fyi, I have a lusitano who is branded on right hip. Maybe that’s a southern hemisphere thing, but who knows. Just don’t presume anything if looking for a brand. I wish you luck, its like a mystery begging to be solved.
