Appearances in Christmas specials
"Christmas Flintstone", the Christmas episode of the original series, naturally marks Pebbles' first appearance in a Christmas special. Early on in the episode, Fred tells her and Wilma that he's gotten a second job at Macyrock's Department Store, joking that he is now eating for two jobs, though Pebbles does not find that joke funny. Later, when Fred does a successful performance as the store's Santa Claus and even does a television interview, Wilma and Pebbles are seen watching Fred's interview. She is last seen at the end of the episode, when the two families have gathered together for Christmas.
Chronologically, Pebbles' second appearance in a Christmas special is the franchise's fourth Christmas production, A Flintstones' Christmas Carol. When Fred wins the role of Ebonezer Scrooge in the Bedrock Players' production of A Christmas Carol and starts acting like Scrooge in real life, he even unintentionally ends up neglecting Pebbles, to the point that he doesn't kiss her goodbye when he drops her off at daycare and forgets to pick her up from daycare before heading to the theater (fortunately, Barney picks her up along with Bamm-Bamm). During the play, Pebbles portrays the role of one of the Cratchit family's children, and also says the line "God bless us, everyone!" when Bamm-Bamm (who's portraying Tiny Tim) gets stage fright at the end of the production.
In the series' second-produced Christmas special, A Flintstone Christmas, Pebbles and Bamm-Bamm are of elementary school age, which places the special a few years after A Flintstones' Christmas Carol and several years before The Pebbles and Bamm-Bamm Show. She is seen at the Ladies' Auxiliary's party with the other children, becoming impatient in waiting for Santa (Fred) to show up. After quite a while, Pebbles expresses worry that Santa is not coming, but Wilma sings the song "Hope" to cheer her up. At the end of the special, she and Bamm-Bamm, along with their respective fathers, are shown waving to Santa when they see him flying in the sky.
In A Flintstone Family Christmas, the only Flintstones Christmas production that takes place after I Yabba-Dabba Do! and Hollyrock-a-Bye Baby, Pebbles and Bamm-Bamm call to say that they and their kids, Chip and Roxy, are flying from Hollyrock to spend Christmas with their families in Bedrock. Midway through the special, however, their flight is delayed by bad weather. Fortunately, by the end of the special, the couple and their children eventually arrive at the Flintstone residence in time to celebrate Christmas with their families, including Pebbles' new adopted brother, Stoney.
Outside of The Flintstones itself, Pebbles also starred in "Cave Kid Christmas", the Christmas episode of her and Bamm-Bamm's short-lived spin-off, Cave Kids. As the series takes place when the two are preschoolers, this would indicate that "Cave Kid Christmas" comes between A Flintstones' Christmas Carol and A Flintstone Christmas in chronological order.