If you're paying $15k tax on such an income, you've seriously got to consider moving to another country. No wonder there is so much interest in the TEA Party. In Australia, with those figures, you'd pay no tax (depending on assumptions on depreciating camera gear). Worst case scenario, $2k tax.
Running my small business, I can agree that $15K tax on a $50,000 gross is way out of line, if those numbers are accurate, the photographer needs a accountant, she should be paying $0 tax.
Most likely, she has a $250,000 gross, and after the usual business deductions, deprecation, etc has a profit of $50,000 but pays a alternative minimum $15,000 tax which is imposed for those where the high number of deductions hides too much income. I get hit with the minimum tax some years, but even on $250K gross, I pay maybe $1,500 tax.
Either way, something is wrong with the picture.