Susan runs an animal shelter where Stitch ends up being flung into while escaping from Jumba and Pleakley. At the same time, Nani comes to the shelter to get Lilo a pet to curb her behavior, and Lilo just so happens to find Stitch and instantly becomes fascinated with him. When Stitch is shown to Susan, she gets frightened by his appearance at first, but eventually calms down after Lilo says she wants to adopt him.
In "Sample", Susan calls a pair of "alien hunters" named Merwin and Dean to deal with Experiment 258 (Sample), who had been captured and brought to the shelter.
In "Babyfier", Susan points out that Mr. Patterson, an old dog at the pound, has been waiting for months to be adopted and that his time was pretty much up. Lilo then cleverly unleashes Experiment 151 (Babyfier), who turns the old dog into an adorable puppy. Shortly after, Mr. Patterson is adopted from the shelter by a little boy.
In "Skip", Susan presents Experiment 089 (Skip) to Lilo when she asks if there have been any new "dogs" brought to the animal shelter lately. She then lets Lilo take Skip home with her.
Although her name is not mentioned onscreen, it appears on the adoption papers she has Nani sign.