Shows didn't do flashbacks back then, I guess.

Spoilers of the sixth season.

They did have an episode entitled, "What If." and it was basically that, a what-if show. It was somewhat of a flashback or a vision Bailey had in the 6th season after a brief relapse of alcoholism. It went of an if their parents never passed away and what would they be doing if it had not happened.

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Keep the faith, Matt.

Party of Five never showed flashbacks of the siblings or younger versions of them interacting with their late parents before they died probaly because the writers and creators wern't particulary intrested in showing the parents, Nick and Diane, interacting with Charlie, Bailey, Julia or Claudia in happier times, but to take the viewers into the Salinger's lives by having them move on with their lives.

Even in the Season 6 episode 'What if...' set in an alternate reality where their parents are still alive, the four main characters never interact with them as they try to make their own lives for themselves independently.

In the 'What if' episode, Bailey is seen with a frosted hairstyle, always drunk, and living his his lifelong friend Will, and working as roadies for a local punk rock band. Since his parents never died, Bailey went through and graducated from high school, went to college, began drinking... only he apparently never stopped or sought treatment. As a result, he is in more of a mess in the alternate reality then he was in the contempary one on the show.

As for Charlie, he was shown with a short hairstyle, he shaves on a daily basis, lives in a luxary apartment in the city, and works as a high-paid archetect. In Season 1, he told Bailey that he dropped out of college during his junior year to find himself. He was planning to re-enroll before the car accident that killed his parents. Since his parents never died, Charlie never took over running the restaurant, he did go back to college at Berkely, got his degree, and found success in his new profession. But in so doing, he never met or become involved with Kirsten, and he also never grew up. He was shown to be single and still having one-night stands and being the same immature, womanizer that he was from Season 1.

As for Julia, since her parents never died, she apparently never grew up either and apparently dated Justin Thompson off and on throughout her high school and college years. She never traveled the world or became rebelious, she never cut her hair short, or ever met Griffin Holbrook.

In contrast, Claudia grew up, but apparently too fast. In the 'What if' reality, her parents probally pressured her to become a prodigy in playing the violin and she dropped out of school at age 12 or 13 to go on tour playing the violin and traveling the country and the world, making money, meeting new people, and even having a taste of the real world. Claudia reveals that she is not a virgin in the alternate reality, whereas Julia apparently still is. (It is the other way around in the contemporary reality; Claudia is still a virgin, while Julia isn't).

Since their parents never died, they Nick and Diane currently are raising Owen by themselves, so there was no reason for any of the four older siblings to remain around their parents as they sought out to make their own lives for themselves... yet they all came together only to celibrate their parents 31th wedding anniversary party in the closing scene of that episode.

There were (small) flashbacks in another episode. I forget which episode/season but it's when Charlie, Julia and Bailey go to the old cabin they used to stay at with their parents - they had flash backs of them as kids playing in the snow.

yeah i guess back in the days, the writers weren't as lazy...