How can she fix this?

Wait a second... She was given medications for depression and YOU think she is not sick? Like, you don't know their official diagnosis, but YOU think they are not sick, and they don't need the medication? Hmm... I'm confused...
Now if you are basing your question on the fact that you whole heartedly know that the doctor pushed a medication without a diagnosis, then I can see an issue, but if you are just upset at the fact that your niece might have issues with depression and needs medication to overcome it, then you don't need this question answered, you need to find out about depression, or depressive disorders.
Depressive disorder can require medication that is taken year round because it is supposed to regulate the chemicals in the brain so the depressive cycles aren't as severe. When it comes to brain chemistry a lot of medications don't work instantly, and the ones that do, are usually in the narcotic category.
So, as I said, are you just upset that they are on medications when YOU, personally, don't THINK they need them, or do you unequivocally know, for 100% fact, your niece does not need them? Like, you heard her, her mother, the doctor, all say "she doesn't need this" then they gave it anyway.
As far as the last part about her job, why would a job care about her personal doctor visits, and why would they fire her for seeing a doctor, getting treatment, and needing a medication? I personally, even after being a government employee, can't think of a single job where your mental health diagnosis would get you fired, or your contract ripped up. Might get you moved around to less stressful jobs, or areas, but never fired. I mean it probably would be against the Equal Opportunity Act, the Americans with Disabilities act, and maybe the Rehabilitation act of 1973.
I guess the question needs more context in order to get a solid grip on what it is you are wanting to know, because this can only be one of two things. 1. You don't like medication, or 2. the doctor is grossly incompetent.
Okay, so, hang on... Her mother feels that she doesn't need it, but the doctor, officially, believes that your niece needs the medication in order to treat her depression, which could or could not be long term, she just needs it for right now. Correct? How will the medications affect her job? Is this referring to the normal urine screen done for work?
But the worry is about her job, correct? If it's the urine screen all she needs to do is keep a copy of her prescription with her, at all times, so she can show proof that she has been prescribed the medication. If the medication is just for sleep, like Ativan, or Lorazepam, it's only for around a week, or 2 weeks. Especially if she is new to the medication. Something like that just helps someone relax so they can naturally fall asleep. It can be habit forming, but usually it takes more than 2 weeks to get a craving for it. That's why they try to keep it around that time frame. All in all medications aren't going to ruin her, or her job prospects, or her career, just as long as she can prove she is taking the medication that comes up. Same with pain meds. We get them for tooth extractions, but as long as we can prove a doctor prescribed them, work usually doesn't care.
If the doctor truly feels she needs something long term, then maybe her mother should ask to speak to him, one on one, and find out what the diagnosis officially is and then share her concerns with him. That way everyone feels like they are part of the conversation, if that makes sense. If she is over the age of 18 and is independent from her folks, then her mother and everyone else, should just have trust in her doctor, and in her decision making skills, and accept it as it is. That can be hard to do because we want to protect family, but sometimes things are out of our control.
Well that's what I'm trying to figure out. WHY would she lose her license? Why would she LOSE her job? is she on probation? Is she on parole? Does she have priors with local law enforcement? Does she have a contract with her current employer that says if she takes any sort of substance, even from a doctor she will be terminated? Why do people not trust her on her own? I feel like there is more to this situation. Has her mother gone to the doctor and explained these reasons? Usually if a parent explains why their child can't have a medication, the doctors will change the prescription. So her and her daughter should probably go to the doctor and talk about it. That's probably the best thing they can do.
Doctors usually don't prescribe meds without reason, so she probably need the meds for some ailment.
And why would this endanger her job? If there is a reason for the meds, a doctor could also write a sicknote and she would be excused from the job.
Opinion
2Opinion
She must have mentioned something to her Dr about her feelings, for him to prescribe the meds.
Keep taking her meds or see another doctor.
Then toss the meds in the trash.
That's not the end of the world.
Superb Opinion