Cause of death still pending after 6 months; what is taking so long?

My mom passed suddenly and unexpectedly about 6 months ago after returning to the home she was at after a short outpatient surgery. She left the hospital in stable condition. She returned to the home and 2 hours later died. The home failed to follow her discharge instructions. I have been in touch with the coroner and an attorney but almost 6 months later nothing! No autopsy was done. The coroner was unable to perform one since my mother was already embalmed at the funeral home. My question would be, how long in the state of Pennsylvania until there NEEDS to be a cause of death on the certificate? And what is taking so long? I am suffering from anxiety due to the nature of my mother’s death. My mother was not involved in hospice nor was she in declining health and was 55.