The Kidjo subscription is on the list of restricted content that cannot be shared through Family Sharing because it is an in-app purchase. For more details, follow this link: https://support.apple.com/HT6389
To share a subscription, complete the following steps on each of the devices with blocked access to the videos:
- Open Kidjo
- Create a parent account. It will connect to your ongoing subscription
- Open the device you want to add to Family Sharing
- Log into the parental account created on this device
- Your kids' profiles and videos will appear automatically.