They are a married couple whose shared household anchors Lady's domestic life.
The plot identifies Darling as Jim Dear's wife, and later describes them as a couple caring for their baby.
Jim Dear is Lulu's father and guardian.
Lulu is born to Jim Dear and Darling, who later protect her during the nursery attack.
Jim Dear provides Lady with a home and ultimately accepts responsibility for her safety.
On Christmas Day, Jim Dear gives Lady to Darling as a puppy, and later brings Lady home from the pound.
Aunt Sarah temporarily supports Jim Dear's household by dog-sitting.
Jim Dear and Darling leave Lady in Aunt Sarah's care during their extended visit.
Jim Dear ultimately turns Tramp from a stray into a household member.
After Tramp is injured, Jim Dear and Darling adopt him as their own to protect him from the dogcatcher.
Explore the full interactive character relationship map of Lady and the Tramp