ALL parrots love fat [I have an ARB that I have to hide my buttered bread from because she will steal a beakful of the butter any chance she gets
]. High fat and high protein [both characteristics of marrow] are seldom found in large quantities in nature so they have a craving for it. But animal fat is real, real, real bad for them because, with the exception of a couple of species, all parrots are herbivores so the only kind they get is vegetal fat never animal which has a lot of cholesterol -something parrots did not evolve to consume at all as only animal fat has bad cholesterol in it. I would STRONGLY recommend you stop feeding your gray animal products because all that animal fat is going straight into her liver and her arteries. Has she had a bile acid test lately? If not, I suggest you do one and see how her liver is doing...