Having your test information on a profile does not prove you are descended from that person. It only means that your ancestral line currently shown on WikiTree connects you to her. You need to analyze your DNA matches to see if they support that conclusion.
If you do feel confident that your matches show you are descended from Ruth, then you can refer to documentation showing that Ruth is indeed the daughter of Sarah. It looks like there is documentation on the profile now, but I would caution you that Brown is a very common name, as I know all too well from my own ancestry, so you need to study it carefully.