DR TCB Betty Jo the youngest and only married Bradley sister was always played by Linda Kaye [Henning] daughter of the creator of the series Paul Henning (he also created the sister shows HILLBILLIES & GREEN ACRES and was one of the creators of Love That Bob - The Bob Cummings Show - starring Bob Cummings).
Meredith MacRae played the oldest and blondest girl Billy Jo (among others including Jeanine Riley) and Bobbie Jo, the tomboy and middle girl with long raven hair was played mostly by Lori Saunders - who could be very funny....
Bobbie Jo comes in from school out of breath and collapses on the couch....
Kate: What's the matter, Bobbie Jo?
Bobbie Jo: When Walter Huggins says he's gonna run you home from school.....he runs you home from school!