So...two chapters for the monster, one chapter for a tearful reunion with Pops, one for faffing about before proposing, and then a wedding+ten-year time skip epilogue?
Well, if Greek mythology told me anything, if you are against something that can turn everything to gold you just have to wait until it starves to death.
Some interpretations of medusa are what she sees, and most when you look into her eyes. Depending on what happens to energy based attacks, etc, and given that the gold-ification seems to include equipment, medusa could be easier with a blind wide area magic. Otherwise you might be limited to chucking large objects and hope goldy doesn't have amazing armor that can withstand that items' new gold-ified weight.