How do I stop the timer?

Any one of these:

• The square stop button at the left of the bar at the bottom of the screen.
• The round stop button in the card on Home.
• The stop button on your lock screen.
• Siri: "She woke up in Veilleuse", "Done feeding in Veilleuse".

Wherever you stop it, it stops on every phone of the family at once.