Little Sadie Miller is devastated.
Lindsay: "Do you want him to stay young forever?"
Sadie: "Yeah he's so cute."
Lindsay elaborated, "It was the first time that she had kind of put together that if everyone grows older that he's gonna grow older too."
Even during our Facetime interview, Sadie couldn't stop fawning over three-month-old Carson.
"She's been a little into him ever since he was born. So when she put together that he was going to get bigger, it was pretty traumatic for her," said Lindsay.
The doting little sister is clearly a deep thinker.
Sadie: "I don't want to die when I'm 100."
"She was really upset. She's been talking a lot about death and we told her that she won't die for a really long time, until she's like 100, but that upset her even more," continued Lindsay.
Even with all the tears Sadie can't resist baby's charm.
"Oh you are so cute. I love your cute little smiles. Oh my gosh! I want him to stay this little," exclaims Sadie in another clip from the video.