“Sure, I can wear a diaper, if it’ll make Katie happy,” Kelly said with a shrug. “I will need a bit of help with it, though.”
“You want me to diaper you?” Jen asked. Kelly nodded. “…All right.” Jen picked Kelly up and put her on the diaper changing station, where she proceeded to remove Kelly’s clothes, then tape a diaper on. “Katie wants you to be like a proper baby sister, so that means you can’t wear your proper clothes. Is that all right?”
“As long as I can wear something, I’m happy,” Kelly said.
“All right. Stay right here, I’ll be right back.” Jen left. A few minutes later, she returned, holding a fuzzy pink onesie. “How’s this?”
“Looks great.” Jen helped Kelly get into the onesie. “Okay, time to go play with my big sister!”
“Okay.” Jen carried Kelly back downstairs. “Katie, your baby sister is ready to play with you!”
“Yay!” Katie cheered, jumping up and down. Jen set Kelly down next to her niece. “You get to be the baby, so you do baby things!”
“Yes,” Kelly said. “I do baby things.”
“Is there something you’d like your baby sister to do?” Jen asked Katie. Katie nodded. “What do you want her to do?” Katie grinned. Suddenly, Kelly was worried about what babyish thing her niece wanted her to do.