Her joy certainly shines through in her new music video, which stars the adorable eight-month-olds.
Mariah's husband Nick Cannon also stars in the clip for When Christmas Comes, her duet with John Legend.
It's hard to believe that 17 years have passed since Mariah topped the charts worldwide with All I Want For Christmas.
The 1994 hit is still a Christmas favourite, something which Mariah says makes her feel "amazed and humbled".
She has released a new version of the track this year – a duet with Justin Bieber.