Well, since caseyburns95 was right about Mars being the child of Juno and Jupiter, maybe those are the alternate names. Isis being Juno and Osiris being Jupiter.
Isis is the goddess of fertility and motherhood, and even though Juno is a goddess of the law, she is also Hera in Greek mythology. Hera is the goddess of women and marriage.
But, Osiris is the god of the underworld while Jupiter/ Zeus was god of thunder and the sky. Opposites.
That's the only thing I've got. I'll look more into different possibilities.
That's what I thought, too, after I learned that Horus/Mars was their kid. I thought they were friends, like casey, but it would make a ton more sense if they were his parents.