I don't like Sailor Moon anymore, I watched when I was around 4, so heck.
Anyway, I don't know anything about Wedding Peach, but I remember hearing people talk about it once, so I went to a place where the description was, and it did sound VERY similiar to Sailor Moon, whether Wedding Peach is a rip off of Sailor Moon, or Sailor Moon is a rip off Wedding Peach, I have no idea, I leave it up to you, but before you say anything, compare the dates of when they were released in Japan (not in the States, they normally release the most popular one first) so you decide, and even that does not mean anything.