Why can’t my family see my new child?

When you create a timeline for a new child on BackThen, it is not automatically shared with anyone, not even existing contacts of other timelines - this is to avoid any risk of a private timeline being accidentally shared with people you don't want to share with.

For each of the contacts you wish to add to your new timeline, you need to add them. For more details on how to set permissions for each contact, check out this guide.