This is the only appearance of Holodeck characters Flotter & Trevis, but the doll of Flotter is seen occasionally in future installments.
Not for the first time, the phenomenon know as "Soap Opera Rapid Aging Syndrome" is employed on a Star Trek show (a concept which television soap operas often employ to accelerate the ages of child characters so they mature more quickly for the sake of narrative expediency). In this case, Scarlett Pomers assumes the role of Naomi Wildman, who was born on Voyager during season 2. Naomi would only be around 2 years old by the start of the fifth season, but Pomers was 9 years old when it was filmed. This is explained in a trivia entry for another episode. Naomi's non-human DNA caused the more rapid aging as a young child than that experienced by humans. This is also the explanation for Worf's son Alexander's rapid growth on Star Trek: The Next Generation (1987).
Harry Kim, Samantha Wildman, and Captain Janeway mention that they thoroughly enjoyed the Flotter "holostories" when they were children, with Janeway claiming to have flooded the entire Forest of Forever when she was six. This suggests that some form of holographic technology was in use as a recreational device for children long before holodecks were in use on starships.
47-reference: Starfleet Regulation 476-9 states that all away teams must report to the bridge at least once every 24 hours.