There have been a variety of papers published on the indications for hysterectomy, a topic I won't get into at this time. However, the complication rates will vary depending on the reason for the surgery. The deeper issue here is the problem of interpreting whole population data for a specific patient. Many, many factors influence complication rates. People with more severe underlying disease may be more prone to complications.
Operations performed in emergency circumstances are more risky.
Some doctors are better at certain procedures than others. Therefore, your mother's chance of certain complications depends to a great degree on her, her condition, her doctor, and the other circumstances of her particular treatment. With those cautions in mind, I checked several sources for information on hysterectomy complications. It seems that bleeding, urinary tract infections, and inadvertent injury to the bladder and ureters are among the most common ones. Other structures in the area, like the bowel, blood vessels, etc, can also be injured.