...except that it used to be that your ability to secure a loan was based on where you went to school, how firm your handshake was, and if you happened to have the right skin color and sex organs.
The current system certainly isn't perfect; and if you're denied a loan you have a legal right (in the US) to know the reason.
There are systemic issues, to be sure. But the nominal goal is absolutely better than what we used to have.
I'd definitely recommend getting a credit report (not from the websites that advertise with an insane jingle, but from the actual credit bureaus
you're entitled to a free report). Mine had debt from a relative with a similar name; I was able to get that removed. They will also tell you in more detail what goes in to calculating it.
I agree that it's not perfect, and often very opaque, but you should be able to get some understanding of why she doesn't have good credit.