The Brady Bunch (1969-1974) was full of guest child actors, and for every seasoned pro like Pamelyn Ferdin (she laughed at Jan's wig) and Melissa Sue Anderson (she kissed Bobby) there were also green day-players who didn't exactly shine bright in their 1 minute of sitcom time.
The two Brady guest actresses mentioned below have fascinated me for decades:
Teresa Warder played "Seattle Linda" in Season 1's episode called "The Undergraduate"
At the 7:10 mark, Mrs. Brady interrogates Marcia's school chum Linda thinking that she is Greg's mysterious crush. Warder (with her zombie stare and thick tongued speech) is something more apropos for a visit with The Addams Family.
I get such a kick out of Teresa as "Seattle Linda" and could listen to her strange delivery of dialogue all day. Just listen to her say: "SEE-AT-TULL" and
"Wullll, thuz one boy I like, the only problem is - he doesn't know I liiiike 'im."
This phenomenal debut by Ms. Warder on the Brady's sofa was her sole acting credit.
Meanwhile in Season 4's episode called "Law & Disorder", Bobby is made a safety monitor and is pestered by a frantic girl to save her cat Pandora. I call her "Spazzy Jill" as in:
"Pleeease! You've Gotta Get Pandora Out For Meeeee!"
"Spazzy Jill" is played by Ms. Shawn Schepps. Shawn was discovered by a TV casting agent while she emoted at kiddie Drama Class. Her unglamorous yet effective portrayal of a frantic girl worried for her cat's safety is truly memorable.
(see her chew the scenery at the 4:10 mark)
Shawn quit acting by her 20s and later became a screenwriter (Encino Man) and writer/producer on WEEDS - where she returned to guest roles. She went to Writer's Boot Camp and sounds like a good egg (read her alumni info).