Hey Mari. I have not found full proof, yet. This is a common issue with all the family tree information out there - family trees use un-sourced information, that is found on a family tree somewhere, to build the tree out furtther, and it is setting up all the connecting from there on as unfounded and unproved... a waste of time(?).
There is sometimes evidence and association evidence in some sources which can help show that particular information is probably true, such as stories and documentation like writtten stories and memories in family records. Using that kind of information can help set up connections that might lead to more evidence of proof to validate the connection.
