"I wish I could pay you more."
There's lots of advice out there on how to ask for a raise. Lifehacker.com editor Thorin Klosowski suggests checking websites like Glassdoor.com or Salary.com to get an idea of comparable salaries, giving you some leverage when you talk to your boss. But, as Klosowski also writes, sometimes you find yourself in a "salary negotiation where your employer isn't able to give you more money. If you can't get more money, you need to 'expand the pie' by offering up alternatives to a raise ... [and] think of other perks you can ask for that don't require money. This might include working from home for a few days, extra vacation time, shorter hours or any other 'free' perks you might want." Just remember that in these economic times it's often not your boss's fault, and that if you've been working hard and doing your job well, she may well be able to offer some other incentive.