Update 2: Step by Step (1991)

As announced another pic from channel TheRealLatzMan. German title Eine Starke Familie. I had some pics before, younger girl (Christine Lakin), teen girl and boy in bibs/shortalls, rating 6. I think this is Staci Keanan as teen girl Dana. Unknown episode, also similar sitting and standing with belt in s5e2 but other shirt (IMDb). Also in black bibs in another clip.

(I first confound this with his other clip, Family Ties (1982). There's also Tina Yothers in bibs or similar like in s4e13. And Brian Bonsall in red bibs or similar in s6e4 and s7e24, pics on IMDb.) 

I still have to re-check both.

https://biboverallsfilms.blogspot.com/2011/05/step-by-step-1991.html

https://biboverallsfilms.blogspot.com/2014/03/update-step-by-step-1991.html