"The Haikster"

My almost six year old daughter is referring to herself as "The Haikster." I asked her if someone gave her that name and she said she had bestowed it upon herself -- except that no one else is allowed to call her by it -- not Mom, Dad, siblings, friends, teachers -- not a soul -- except for "The Haikster". Being curious, I pursued my line of questioning (I am, after all, a lawyer). I inquired as to why no one else can refer to her by her new nickname and she told me, "Because it's kind of dumb. My friends might me call me that name and laugh." My interest piqued even further, I followed up with the question, "Why call yourself by a name you don't like?", which was met with the reply, "I only like it when I say it. I say it cool." Fair enough, Haikster.