I do not believe they actually exist, with the exception of my dog, who is the least likely of the ones I mentioned to be "prayed to" given that she has some of the same problems I do as well as other faults. I am not asking them to actually give me anything using magic or anything like that. "Praying to them" is probably not the right thing to call it--it's more like thinking about them and the thought can sometimes help me in difficult situations, since both of them have had fairly tragic lives; one of them had to escape from his/her dying, ravaged planet, and the other had her city destroyed, she was pursued by the Black Moon family, and she didn't even have two other friends to help her. So the thought that if Chibi-Usa-sama could go on after that, especially at her age, did help me at work one day. (I imagined her scolding me, actually) But only that one time. As for Taiki, I can't say that it has helped me to think of her sometimes, though, it's more of a wishing that I could handle unwanted attention as well as I think he/she does. (others may disagree on that) In Diana's case, it's not a matter of praying to her, it's more just wishing that she could be with me because I love her so much.
I apologize for calling it "praying," that's not the proper term for it at all. Sorry for being confusing. I know very well that the only one of the three who can give me anything, really, is Diana, and that's only by her furry prescence.
By the way, I'm surprised no one noticed this, but I should've put this topic in the Sailor Moon section. I'm not quite sure why the heck I put it under "off-topic" when it's about the Sailor Senshi.