Hey man you can try to tell her that, but she won't buy it. Many pathologists have tried to play that card before actually. Just tell her that it isn't the size of the axe, its how hard you swing it, IYKWIM.
I'm not aware of studies addressing your question. Some of the autopsy texts include tables/% changes between pre and post formalin fixation for organ weights, but I don't recall seeing the same for sizes or a formal comparison amongst tissue types for "shrinkage."