1992’s “Poison Ivy,” starring Drew Barrymore, centers on a plot familiar from other films—an alluring figure insinuates herself into a family by charming the children and captivating the husband. This setup recalls movies like "The Babysitter" (1980) and "Summer Girl" (1983), both made for television and accessible online. In “Poison Ivy,” Barrymore portrays Ivy, a friend of the awkward Sylvie (Sara Gilbert). Tom Ske…