Great to read you want to prove the relationship, that is the way to go!
If you go to their profiles, you should see a section with sources. There the documents are shown for that profile. Proving your relationship means adding sources to your own profile, that of your parents, grandparents and so on.
If the source is not there, you will need to find it. If those sources don't exist, then the relationship is unproven/untrue/fake (choose your own wording).
The best way is to start by adding your own ancestors and work from there, towards Prudence and William. You did not give their profiles so I personally do not know how much work is involved in that.