I checked her IMDB page, and there are some possibilities.
One that caught my eye was an appearance on an anthology series called The Danny Thomas Hour, that ran between 1967-1968. I don't know if that coincides with the Robots show, but Thomas had played her on-screen dad many years earlier. It looks like the episode was possibly an unsold pilot or a special, as it was called "Make More Room for Daddy" and she plays the same character. Angela became a popular star on the original show, at age 6.
She also shows up on My Three Sons and The John Forsythe Show during LiS's run perhaps, though both of those are dated as 1965.