How to tell if a page is fake?

[YodaKnows]

There's this page on facebook who claims to have known a relative of mine before they passed away and I have never met this person before, they even put my relative as their profile picture. I was really close with this relative too and there's no way to know whether or not this person is lying. Just something seems kinda strange about this page and something about the page seems kinda fake. Like one time he posted this picture of someone who he said was his great grandmother, but when I googled the picture, I found that exact same picture all over the internet. I asked him about it and he still tries to say that is his great grandmother but I just find it strange because he claims to know this person close to me and I've never heard or seen him before in real life, even though it's just possible I've never met him but at the same time the picture he posted of his supposed grandmother was all over the internet so I don't know what to think about this. What do you think?