If you have Admin access for a child's profile, you can manage others' access.
Tap on your profile image or initials (iOS) or Account icon (Android)
2. Tap on My family
3. Tap on your child's name:
4. Tap 'Add admin' if you want to update your partner's access, from Story to Admin access (or invite a new Admin):
You'll get a pop-up asking you to confirm your decision: