Create a breadcrumb, b1. Create a child, b1_1. Delete the page associated with b1. The child still exists, but there is no way to edit it or delete it.
select to_char(id), * from flows_02000.wwv_menu_options
where flow_id =
find the option that you want to edit. Copy the id.
Edit a different menu option, you'll see a link like the one below:
change the final number to the id you copied.
Voila! Now you can edit your menu option and give it a new parent.
Hope this helps someone.