She is a nice looking mare. Definitely no tattoo on that lip. When there is one its usually pretty obvious. The shoe brand you describe isn't info on what she might be. Ill be honest tho, to me she doesnt look like a tb at all. Her build screams QH to me. She has the hind end and shoulder of one. I would see if a vet can read a chip on her. Some horses are chipped which will give you the info you need to start your search.
She's a really nice looking mare. Her shoulder is a little more steep than what I would like to see, but she is really cute otherwise.