Jessie James Decker is pretty chill when it comes to her kids’ eating habits. The country pop singer — who shares four children with her husband, Eric Decker — opens up about parenting during an exclusive chat with OK! while promoting her partnership with think! and the brand’s new think! MINIS Protein Snack Bars. Reflecting on how she went about raising her daughter, Vivianne Rose, 10, as well as sons Eric “Bubby” Thomas II, who turns 9 on September 3, Forrest Bradley, 6, and Denver Calloway, 6 months, Jessie admits: “I started feeding my kids real food as soon as they could chew.” “I always …