Sinéad O'Connor's daughter sang with her on Icelandic TV

Roisín Waters and her mam join John Grant on Icelandic chat show for a song called 'Greatest Motherf***er'.

We missed this at the time - not being in the habit of tuning into Icelanic TV on New Year's Eve, surprise surprise - but Sinéad O'Connor's daughter Roisín is a chip off the old block.

Roisín and her mam joined US singer-songwriter John Grant

for a special edition of Icelandic chat show "Sunnudagsmorgunn" on December 31.

Grant was singing his tune GMF 'Greatest Motherf***er' (GMF), one of the most popular songs of the year in Iceland, when he introduced his surprise backing vocalists.

Not so much of a surprise is that Roisín - Sinéad's 17-year-old daughter by writer and Irish Times columnist John Waters - has a lovely voice.

We think mother and daughter make a great double act, but judge for yourself in the below clip (WARNING: NSFW for language)

Sinéad and her daughter were visiting Iceland over New Years', the singer having fallen in love with the country during a previous visit, according to The Reykjavik Grapevine.

„I came here and did the Iceland Airwaves two years ago, that's why I wanted to come back with my children,“ Sinéad told the show's host Gísli Marteinn.

Grant, originally from Colorado but now based in Iceland, achieved critical acclaim with his 2010 debut solo album 'Queen of Denmark'. Sinead is a long-time collaborater and features on his second solo album, Pale Green Ghosts, released last year. He's doing an Irish tour in March.