Prince William, 31, returned home early from his University of Cambridge classes to celebrate his wife's special day. (As previously reported, William is currently taking a 10-week program on agricultural management.)
The Duchess of Cambridge's party guests included parents Carole and Michael Middleton, siblings Pippa and James -- and, of course, her 6-month-old son George.
Asking housekeeper Antonella Fresolone to whip up a meal (her speciality: Italian!) "was easier than going out and leaving George at home," a source tells Us Weekly.
The simple affair was exactly what the new mom wanted. The insider explains: "She doesn't like a big fuss."