The Third Sunday of Advent, is also known as Gaudete Sunday, where the priest wears ROSE vestments as opposed to the PURPLE or VIOLET he wears on the other Sundays and weekdays of Advent. Since the pontificate of Pope John Paul the Great, it is also called Bambinelli Sunday to commemorate the blessing of the Gesu Bambino (baby Jesus). Children of Rome flock to Saint Peter's Piaza where the Pope blesses the figurines of the Baby Jesus which the kiddies bring from their homes and then return them in time for the family display of the Nativity Set (Christmas Creche). According to a Zenit article, the Nativity scene has been part of Italy's culture for almost 800 years now. According to tradition, St. Francis created the first representation of the birth of Christ in the little town of Greccio in 1223.
Many parishes across the globe now honor Bambinelli Sunday by having the Pastor, Parochial Vicar or Deacon bless the 'baby Jesus' which each family brings to Mass that weekend. We normally ask the youngest ambulatory child to bring up the figurine and sometimes they are accompanied by their siblings. Even the adults, however, bring their little baby Jesus from their Nativity Sets, and get them blessed every year. This can be done BEFORE Mass begins or AFTER Mass ends or it can be done later in the day at noon or three o'clock (hour of mercy). BTW, if your parish forgot to plan this in time for this weekend, no harm in doing it next weekend on the Fourth Sunday of Advent (just one time).