Meg has twin Imperial Gold blades that are in the form of siccae blades. They are hidden in two rings that have wheat symbols, her mother Demeter's symbol, on them. How she got her blades is still a mystery. Apollo asks about it in The Hidden Oracle but Meg tells Apollo to stop and doesn't answer him. We can assume that they were given to her by Nero since she doesn't want to talk about it to Apollo. At this point, Apollo doesn't know that Meg is a double agent, much like Luke and Silena in the Second Titan War, so telling Apollo that Nero gave them to her would blow her cover.