The pair sang 'Away in a Manger' and wore matching sparkly tiaras.
The self-proclaimed 'Queen of Christmas' has an understudy.
Mariah Carey brought her 11-year-old daughter Monroe on stage for a concert in Toronto over the weekend.
It marked the singer's first live performance since the onset of the Covid-19 pandemic.
The pair sang 'Away in a Manger' and wore matching sparkly tiaras.