A young girl finds a clock in her mothers things.
It transports her and her brother to a land with puppets monsters.
One of them was a rock formation dad and baby.
The brother and sister have to wake a sleeping giant to put their clock on a table, with other kids clocks who also had gotten them from their parents.
You are thinking of “The Argon Quest” 1990. The movie was made from several episodes of the Canadian TV show “Blizzard Island” being pieced together. The show was abruptly canceled after one season. Most of the show is on youtube and the movie is available as a VHS on amazon. Drove me nuts too. Enjoy!
http://www.tvarchive.ca/database/19449/blizzard_island/details/