My grandmother had cancer in other areas and its been removed. she has cancer also in her bones, how fast does bone cancer spread?

Likely not from bone: From your question, it sounds like your grandmother has previously had cancer and it was treated. The cancer "also in her bones" is most likely the same cancer. Most likely what is there has spread (metastasized) from her primary site, i.e., the cancer you are talking about is already a product of "spread." While unlikely at her age she has a primary bone cancer, please clarify with her physician.