Clue #1 - Ruby's Diary

Okay okay, typically im not one to snoop in my sisters stuff, but I had too.. after the cops came and looked through her stuff and left it all, I need I had to look for answers myself..

I found something from her Diary, apparently she had a tumblr blog?? I didnt even know she was like, apart of Tumblr. Thought that was some hipster thing.. I couldnt find much on her blog, mostly about me.. which.. sucks to read but, I shouldnt read to much into it. She talked about MEX-S, even linked their website.. Maybe that site has a clue? I'm not sure though.. https://www.tumblr.com/rubyrose99

When i clicked the MEX-S link however, it didnt work..? I think something is bugged with the site. Hopefully its nothing serious... I'll see if I can find something out.