My guess is That 70’s show.
Re CDAN Blind:
I’m stuck on the decade span of time. Good guesses!
Mickey Mouse Club... Annette Funicello?
Parameters: Show on at least six years (actress was tween when started, adult when finished, so minimum 12-18 ages.)
Lots of under age guest stars and cast members rolling through.
Wholesome atmosphere projected.
Lots of molestation on set from older actors and studio people.
Had a counter part on another network. Rules out That 70s show. No tweens, no wholesome images. Kunis was the youngest cast member at 14.
Only one I can think of that meets all the variables is Fresh Prince/Family Matters.
There are a lot of shows that could be guessed, but without an era or more specifics, that's all I got.