There'll be cases in Funnel where either two siblings have been created with two separate families, or a lead has two families associated to them that should be one joint family.
This can occur if mum, for example, submits a form for her son Clancy with no reference to dad. Later, dad submits a form for their second child, Molly, with no reference to mum. The system has no way of knowing these leads are connected.
If you're sure these leads are siblings, you need to merge the 'Families'. Select the three dots in the top right of the Family widget and select merge family.
Then, in the pop up modal, type to search for the second family name, and select the correct option from the list. Review the family details, and once you're happy, select Merge Families.
This will bring the guardians together as one family and add the sibling details as shown below:
Duplicate families associated with one lead
This could occur if mum submits a form with her full name 'Janet' and then uses her shortened name 'Jane' on another form, creating two families associated to one lead. In this instance you can merge the families as shown above, and then merge the duplicate guardian within that family.