I finished all our OCs as sims, it took forever lol. I tried to make them look as you described, and I tried to give them appropriate clothing for the time period but Sims 4 doesn't have that much 60s clothing. I'm sorry if they don't look exactly as you envisioned them but...

Anyway, here they are:

I also took some singular shots just in case:

Bessie:

Holly:

Ashlynn:

Poppy:

And last and least, Sarah!(my OC) If you ever curious of what she looks like.. Here, I guess:

And uh yeah. I'll roleplay now. (That took all day... Right now as I'm writing this it's 5:21 pm)

Yep. Time to roleplay I guess. Hehe