Can I register my Horse as a paint?

So I just recently rescue one of my favorit horses from slaughter, long story of how she went from not ever for sale loved lesson trail horse to possibly being slaughtered for lion food in canada. Anyway I know she is pure bred paint i am not sure who her parents are or who owned them i just know at one time she may have had papers. she is definitely a paint though, not just a pinto. she is a solid white paint with what would be chestnut/sorrel not sure what the color term is for paints and white because she has mild flecking on her supposed to be color patches. she has dark eyes and pink lips and clearly vi sable dark patches of skin when she is wet so you can tell she should have color and I know she throws color babies. She is 9 years old. i would like to breed her eventually which is why i would like to register her but i am not familiar with paints and registering anyway since i have never done it except for my pinto arab cross gelding and well that registry is not very strict. is it worth it to get her registered and can it even be done with no clue on her lineage and her age?