Samantha and Callie love each other. They're a great match as sisters. Callie insists that Sammy jump on the trampoline with her (which really is Sammy's trampoline anyway) and Sammy loves jumping with Callie. See what I mean? Great team.
Here, Sammy giving that older sister glare to the younger. I imagine her thoughts to be something along the lines of... "You're so embarrassing. Gosh." "Duh." "Um, what are you smiling at?"