When Wade & Polly are in their house, soon after Wendy died, the calendar on the wall changes from 6 to 11.
The character in this episode played by actress Jo Helton is named "Wendy". "Gunsmoke" is set during the 1870s-1880s. The given name "Wendy" for girls did not exist prior to author J.M. Barrie creating the character Wendy Darling for his play "Peter Pan" in 1904.