Storypark only allows one parent to be invited for each child, so that there is less chance of the wrong parent being invited for a child. That does mean though that when one parent has been invited, they need to invite the other parent as family. However, there is a way they can give them the same visibility of community posts, planning notes and ability to invite other family.
The first parent can make the other a “Family Admin”. To do this, they would need to go to their family page and find the other parent’s profile. When they click on the drop arrow in the top right, they should then select “Make Admin”.