Are child beauty pageants good for childrens self esteem?

My neice is 5 and has low self esteem because all of the white kids make fun of her at school. They call her names because she is biracial but is dark and looks 100% black. On Friday, when her class exchanged valentines, she did not get any, and the teacher saw nothing wrong with it. Is enrolling her in a child beauty pageant a good way to help her self esteem?