Mariah Carey is incredibly busy promoting her new holiday show, Mariah Carey's Magical Christmas Special, featuring Jennifer Hudson, Ariana Grande and more, but that hasn't stopped the iconic star from dreaming big – and petitioning to meet the Queen!MORE: Mariah Carey opens up about bipolar disorder after years of 'denial'Taking to Twitter on Tuesday, the singer, 50, shared a picture of three rickshaws, which carried posters of her new show, crossing Westminster Bridge and captioned it: