Diving to Heaven

Mia's response to Sam's departure appears age-appropriate and empathic.
At the suggestion of the vet- a lovely woman who'd lost her dog when her daughter was Mia's age- we'd warned Mia last week that we were taking Sam to the doggie doctor and she might not be able to come home. We explained that Sam was old and very, very sick. Mia understood this - Sam's illness had been obvious even to Mia. She repeatedly told me that the doctor was going to make Sam better. (Yeah, try holding it together when your daughter tells you that.)
After Sam passed, we explained to Mia that Sam had died, her body didn't work any more and we wouldn't be able to see her again. Mia listened, looked at me and repeated, "Sam died. Mommy sad." then returned to what she'd been doing.
Yesterday, when Mia got up from her nap, she immediately brought up the subject.
Mia: "Sam dived."
Me: "Yes, honey, Sam died."
Mia: "Did she go in the swimming pool?"