Answer: Gwyneth Paltrow
The couple's friend Gwyneth Paltrow, who celebrated her 40th birthday this year in Beyonce’s company, sent the tweet. Paltrow is married to Coldplay singer Chris Martin and the two couples are good friends — they even reportedly planned to go on vacation in a Winnebago together this summer.
Welcome to the world Blue! We love you already.— Gwyneth Paltrow (@GwynethPaltrow) January 8, 2012