The best test for Candida is to take a drug called nilstat (nystatin) 3 times a day for 2 weeks. If she gets a die off reaction (feels more sick, feels tired, irritable) during this time or her symptoms go away, then she has Candida. If she feels no change at all, it's something else.
During this time she cannot eat any food with Sugar and she must limit bread products. These foods feed Candida and it's possible the anti-fungal will not work if she's feeding the Candida.
It's quite possibe she might feel a lot better or a lot worse just changing her diet like this. If she changed her diet, I'm sure a lot could change from there, she has to take this first step before trying to "fix" Candida, many of her health problems could probably resolve themselves without a "magic bullet".
There is no "magic bullet" with Candida. If you want a real long lasting cure, you need to put in the work and you need to change your diet.