It is very difficult to get a Thai woman a tourist visa, it is more difficult if she is young and pretty. The older she is, and the uglier she is, the easier it is for her to get a visa.
Nonetheless, she still has to qualify. It helps if she has property, assets, bank accounts, and significant cash on hand.
It was impossible for us, we tried a tourist visa, and we tried a student visa, both were denied. We only got the visa once we were married, and then we got a 10-year multiple entry.
If she is wealthy, comes from a wealthy family, or owns many properties, that might help.