Kinda is, actually. When the Asgardians reincarnated at the start of J. Michael Straczynski's Mighty Thor run following the end of Civil War, Loki stole Sif's body for himself and sent her spirit into the body of a dying elderly woman, intending for said woman's death to drag Sif's spirit into oblivion with her. Obviously, this was ultimately foiled and Loki was forced to resume life as a male, but that's why Fem Loki looks like Sif here.<br / />
When I mentioned Loki had gone female to the gang at the RP group (most of them don't keep up with comics these days), a few started laughing. That was until one of the guys pointed out that Loki is a god of tricks and mischief. That shut a few of them up.