SHE might be one of the most famous women in the world, but when it came to deciding how to celebrate her 31st birthday, Beyoncé opted to keep things low-key.Instead of throwing a star-studded party, attended by all her famous friends, Beyoncé decided to spend the special day with her gorgeous daughter Blue Ivy, seven months, and husband Jay-Z as the family enjoyed a Mediterranean cruise.Jay-Z, 42, appeared to have gone all out to make his wife’s birthday as special as possible, decorating their boat with balloons and streamers in celebration. Beyoncé was bombarded with message from her famous friends wishing her happy birthday. Gwyneth Paltrow lead the way with a handwritten note, writing: ‘For dear sweet BB on the occasion of her 31st birthday...We love you so very much.”        –ES