Here is the second unaired pilot for Three’s Company. For some reason, the closing credits don’t give the name of the actress who plays Chrissy’s mother (neither does IMDb). She kind of reminds me of Barbara Billingsley, but I know it’s not her. She appears around the 11:18 mark:
Chrissy in this pilot is played by Susan Lanier, who was later known as “Bambi” in Welcome Back, Cotter. She was replaced with Suzanne Somers on the orders of TV executive Fred Silverman. In the regular series, Chrissy’s mother was played by Priscilla Morrill, better known as “Edie Grant” on Mary Tyler Moore.
In the first unaired pilot, “Jack Tripper” was named “David Bell,” and his roommates “Jenny” and “Samantha” were played by Valerie Curtin (Jane’s cousin) and Suzanne Zenor, respectively. Fans of The Rockford Files will recognize Valerie as the New-Ager “Sky Aquarian” (called “Miss Aquarium” by Jim’s dad, “Rocky”).