The Alano Dogs have been called the Spanish Bulldog. They are a big, strong dog, with the males weighing up to 90 pounds. The females are bit smaller. They were originally bred as a war dog. They were used in the bull pit, and as big game hunters in and around the 14 century. They were often called the dogs of colors, because they have beautiful brindle coats of many different colors giving the appearance of tiger stripes in some cases. The breed is recognized by the Spanish Kennel Club, in its country of origin. It has an inverted scissor bite to go along with its legendary bite thrust and jaw strength.
In the picture you can see an Alano, notice the pointed ears? These are cropped to form this shape as they are born with ears that will flop naturally over the face, similar to your Betsy's ears.
The breed can be strong willed and quite assertive. The image of your little friend makes me think she may have some of the Alano in her blood, if not full Alano. It's hard to determine without seeing her up close and personal. So many breeds these days resemble the "pit" breeds, and get mistakenly identified, I wouldn't want to make this error as well. The good news is that the Alano can be a very good breed for loyalty and protection of person and livestock. But, always monitor large breed dogs of any kind if you are unfamiliar with its past and personality.
Your Betsy looks like a real sweety!
Hope this helps,