Ruthie appeared in all 7th Heaven episodes of Season 1 - 10. She wasn't in the first seven episodes of Season 11, but further in all the other Season 11 episodes.
Ruthie facts:
Ruthie is the youngest girl in the family. Until the twins are born, she was also the youngest Camden.
Ruthie is very intelligent: she was able to qualify for a scholarship to a local elite private school, but later dropped out and returned to a public
school.
Ruthie often gives her siblings advice about their life.
When Ruthie and Simon were little, they did almost everything together.
Ruthie lives with her family at 527 Alta Road in Glenoak, California.
Ruthie likes making up stories.
Ruthie is friends with a Muslim girl, Yasmin.
In Season 7, Ruthie gets her very first period and she's afraid to tell anyone.
In Season 9, Ruthie dates Vincent. She has also started high school.
In Season 11, she spends time in Ireland, but comes home when her father isn't well.