Penny Robinson had more episodes that revolved around her than almost any other character in Lost in Space except Dr. Smith. Even her brother Will, although much more prominent throughout the series, does not have as many episodes devoted to him unless you count a number where Dr. Smith is in fact the central character.
Over the course of the show’s three seasons, several facets of Penny’s character are revealed. Rather than presenting her as a fragmented character, though, these different glimpses into the mind and heart of the young girl add up to give a good overview of a balanced and not too unusual child.
Penny is early characterised as a tomboy by her sister Judy (“The Magic Mirror”) and she does, in fact, spend a lot of time with Will hunting for rocks or prospecting for ore lodes. But really, what choice did she have? Do boy stuff with Will or stay at camp and work on the hydroponic garden. It’s a no brainer.
With Judy seven years her senior, it is only natural that she should play more with Will, particularly before she reaches an age to be more interested in the things that seem to preoccupy Judy. That she does have a close bond with Will is seen again and again in numerous episodes. The two play chess together (and are pretty evenly matched—Penny wins sometimes, so she must have a bit of the family genius in her). In “My Friend, Mr. Nobody” Will makes her a necklace to cheer her up when she is feeling down. They act in a play together, and are often a pair of companions to Dr. Smith on nature walks and in games.
In “Mr. Nobody,” though, we see an ominous side of Penny’s character for the first time. If Lost in Space were known for its continuity and internal consistency, we might even think it was foreshadowing. Penny, it seems, has a vivid fantasy life. She is friends with a sort of ‘space mimosa’ that drops its leaves when she greets and curtseys to it. With little trepidation she enters into a deeply emotional relationship with a formless voice living in a cave. Her vivid imagination often leads her mother to doubt Penny’s word (in fairness, his parents quite often have doubts about Will’s tall tales too). “Princess of Space” also shows Penny’s imagination—she ends up living out the fantasy of being a princess after mooning over romantic fairy tales.
Another side of Penny’s character is her compassion; this is acknowledged in “The Keeper,” and seen explicitly in “All that Glitters” where she befriends the criminal Ohan. In “The Dream Monster” her natural kindness leads her to water plants during a heat wave (incidentally, this episode also shows Maureen putting Penny’s tale of a golden android down to heatstroke—to the point of actually giving her a cold bath). In many episodes (for example, “The Golden Man” and “The Galaxy Gift”) she befriends aliens on impulse, but always seems to make a right choice instinctively. Penny also develops a very close relationship with the android Verda in “The Android Machine” and “Revolt of the Androids.”
So where does delusional come in? When Bill Mumy revisited and resolved the series’ lack of a real ending many years after in a comic book series, and to a lesser extent, before that in his abortive script for a Lost in Space television movie finale, he had a very intriguing take on Penny’s character. Mumy posits that many of the adventures the Robinsons experienced were in fact the product of Penny’s overly active and rather romantic imagination, recorded in her diary almost in the form of fairy tales, embellished and recast to replace a harsher, more dangerous reality with something more amenable to her own values. It’s not that Penny is psychotic; she is just one of those otherwise sweet and charming children who happen to really, really believe that there are fairies at the foot of the garden. Mumy contrasts this with his version of Will’s view of their life: hard-scrabble, dangerous and dirty; to him, the Robot is just a robot, a tool, not someone he loves like his brother, nor anywhere as versatile as Penny perceives him to be.
Is Penny’s imagination a defence mechanism that offers her some protection against a reality she never asked for, and that may have been too much for one of her tender nature to endure? We may never know, but Tennessee Williams might well have written a few scripts for Lost in Space if he had had the time. One can almost picture a much older Penny moving aimlessly about a decrepit Jupiter 2 clutching a bouquet of jonquils to her bosom as she rambles on about all the gentleman callers she had in her youth—warrior princes, Arab sheiks, giant frogs and who knows what else. Try not to startle her as you walk past.