Actress Brooke Shields has vowed to treat her children to simple but fun birthday parties - because she's sick of trying to compete with other parents' party efforts. The former supermodel has two daughters Rowan, four, and Grier, one, but insists she now refuses to hold any more lavish celebrations for the young pair. She says, "It's hard when you're going to birthday parties that are bigger than Disneyland! "I find myself falling into it. I'm not going to fall prey to it anymore."