From their perch on the carpeted stairs to the second floor, Izzy and Caleb told reporters that their mother’s “big sighs” and “sleepy noises” while preparing dinner were the final clues leading to their diagnosis.

“Shhhhh!” Izzy whispered as Kate began speaking softly into the phone in the kitchen, “She’s doing it again!” The concerned daughter then put her hand over her brother’s mouth as she leaned her head closer to the doorway, straining to catch snippets of muffled conversation.

“’Susan’ is Auntie Sue. And ‘Dad’ is Grandpa Bob,” Izzy reportedly explained to her brother following a puzzled reaction to their mother’s taciturn conversation. Both siblings then scurried upstairs at the sound of Mueller’s slow, approaching footsteps.

Caleb later confirmed that Mueller at one point left the dinner table for seven minutes without even being excused, adding that at bedtime, she seemed to linger at the bedroom door for a “loooong” time after kissing him goodnight. “I get sad like that too, sometimes,” Caleb finished, “So does [stuffed rabbit] Mollie.”

At press time, the Muellers have concluded that mommies get boo-boos, too, but on the inside.