Poor Stylist wants to know if her pay is fair. With 6 mos experience she makes 40% commission but is not making minimum wage. Meanwhile she works the front desk and cleans while an assistant makes more money being paid hourly.
Poor Stylist, this is a loaded question and I can't really answer it, but I can offer some advice.
I would definitely like to see you earning significantly more than minimum wage even this early in your career. Your salon owner probably established this pay method because she sees it as low risk for her (no revenue, no pay) and she doesn't risk overextending herself. Of course she does risk losing an employee that she trained.
My recommendation is that you set up a meeting with your employer. It needs to be a time when you won't be interrupted by phones or appointments, so after work or before the salon opens may be best. You might want to meet on neutral territory like a coffee house. Tell your boss you want to discuss your future and career with her salon. Before you meet, spend some time thinking about what YOU really want out of your career. Of course you want money, but look beyond that. You don't want this conversation with your boss to focus only on money. It should focus on what the two of you can do together to make the salon busier, therefore making you busier. It's ok for money to come up - but my guess is she can't afford to pay your more, which is why you are making so little. (I can't help but wonder why she is paying an assistant when you are there idle - perhaps you should be assisting in your down time).
You need to determine if you are on the same page with the owner. Maybe her understanding was that she would train you but after that you would find your own clients and build your own book. It sounds like you are expecting the salon to bring clients to you. Neither way is wrong - you just need to be in agreement.
Remember that this is a business meeting, so do your best to be professional and try not to get emotional. The two of you have a problem that you need to solve together. Pointing fingers, blaming others and acting defensive is counter-productive.
The tone of the meeting will probably be a good indication of whether you have a future with this salon. If your owner genuinely wants to get you busy I think that will be evident. On the other hand, if she really doesn't care about growing the salon and helping you succeed, I think you will know. If that's the case, be grateful for what she taught you, but move on.