Hard to tell without a body shot, but I could see sighthound, maybe something shepherdy. Xolo seems extremely unlikely unless you're somewhere they're unusually common? You don't tend to get a lot of rare breed mixes popping up in shelters without some kind of explanation.
Then it is more likely she has Xolo somewhere in there than it would be otherwise. Is she a Mexican street dog? If that's the case, she's very likely a mix of a mix of a mix, which makes things harder to pin down - the street dog population there is enormously variable in physical characteristics. It'd be very cool to see what a quality DNA test turns up! If you're trying to get a better idea of what her temperament might be like, you may be better off reading up on Mexican street dogs in general than specific breeds.
I have been reading a ton on Mexican dog breeds and street dogs. She is a year old was taken away from her owner bad situation with her sister. Generally my thoughts are biggest challenge would be housebreaking to go outside and training eventually to be off leash. Most Mexican dogs are extremely intelligent many can be fearful or take time to warm up to new people. I'm hoping for the best that I get to meet her and see how the introduction goes with my other dog and my 2 yr old daughter.