“She has always been super protective of me, especially when my husband isn’t with me,” Brittany Johnson, Diz’s mom, told The Dodo.

A few months ago, Diz’s parents found out they were going to have a baby. Even though Diz definitely noticed, it didn’t seem to faze her at first.

“She would lay with her head against my belly for the first few weeks then she just kinda ignored me,” Johnson said.

A few weeks ago, though, that changed. All of a sudden, Diz decided she had to be next to her mom at all times. It was almost as if her big sister mode kicked in, and she had to be everywhere her mom and future baby sibling were, just in case they needed something. She has absolutely refused to take her eyes off her mom — no matter what.

Recently, Johnson was showering while Diz sat just outside the shower, standing watch. After a while, the worried dog decided her mom was taking much too long in there …

… so she decided to just climb in with her.

“My showers have been longer and she followed me into the bathroom, then just peeked her head in and decided she was gonna sit in the shower,” Johnson said. “She sat there til I was done with my shower.”

Diz must have decided it was too risky to let her mom out of her sight for that long, so she took matters into her own paws.

Johnson is currently 20 weeks pregnant, and before long, Diz will have a new baby sibling. Until then, she’s practicing being the best big sister ever — by keeping an eye on her mom 24/7 until the baby arrives.

“’Cause you know something might happen to me when she’s not watching,” Johnson said.