Kelis wants more milkshakes in her yard...or at least more money in her pocket. TMZ reports that Kelis filed legal papers against her ex-husband Nas to cough up more money in child support. According to the gossip news site, Kelis is saying that the current ruling of $8,000 a month isn't enough to take care of their eight-year-old son, Knight. The original order was put in place five years ago when their son was three. But now, that he's a bit older, Kelis is arguing that Knight has more needs and that those needs come at a cost. TMZ also claims that the paperwork argues that since Nas is a lot more well off now than he was a few years ago so he should be able to afford it. Kelis didn't say how much more she wants, but she does want at least 50 percent of Knight's school-related costs, child care needs and unreimbursed health care fees. This news comes a month after the two settled their custody battle allowing Nas "four full weekends over Januar