From Muppet Wiki

Although Janice was not a regular character on Muppet Babies, she did make an appearance in one episode during the show's last season.

Technically, this younger version of Janice wasn't actually a baby. As a toddler (between 4-6 years old), she was bigger and older than the other Muppet Babies and could read.

Unlike her adult puppet counterpart, Baby Janice could open her eyes and had visible pupils. She also lacked her distinctive purple eye shadow.

In the episode titled "Whose Tale Is It, Anyway?", it was revealed that Bean Bunny knew Janice from their day care center. When Bean wanted someone to be read his favorite story, "The Tale of Peter Cottontail," Janice said that she would do it, as she was the only one who could read. Piggy became jealous and pretended that she could read, even though she really couldn't, and the other babies entered the story-book world, re-enacting the different versions of the story. Ultimately, Piggy and Janice fought over the role of Mother Rabbit in the fantasy segments.

This episode was one of the handful of episodes that was not in regular rotation on Nickelodeon or the other syndication networks after the initial run of the show.

Trivia

Just as the the adult Janice's main performer was a male (Richard Hunt), the young Janice was also voiced by a man, Dave Coulier.