After thinking about this, I don't think they should get paid any higher than what they make now.
The government has to find a way to create more jobs for people, or start formulating ways to fill the voids of the open jobs no with educational reform.
McDonalds is supposed to be for high school aged students, newly arrived immigrants, "rehabbed" criminals, and old people just looking to get out the house and do something.
It should not be a place that adults are settling for when all else has failed.
That's not helping the economy, but actually crippling it by encouraging low skill development through an adult population. In order to keep up with the forces in the global economy, we need more highly educated people with degrees/skills they can use, not people watching fries.
The problem with McDonald's wages is that adults are living on it now, which wasn't the case more than 15 years ago. Most high school students would love to make +$7.00/hr.
The problem isn't McDonald's following minimum wage laws. The problem is our government is too lazy/uncreative to make meaningful jobs elsewhere.