I dont have all the info about your mothers medical history or current condition. But low BP could be a culprit for renal insufficiency secondary to low perfusion pressure. But again its just a thought. Head injury in this age group could be a much bigger problem. Hopefully she will be fine with good care and monitoring.

Her injuries may be affecting her renal function or there may be staffing levels or other reasons for placing her there. Discuss your concerns with the care team and be sure that you are heard. Good luck to you both!

Stop Morphine

Very sorry to hear about your Mom's injury. Perhaps she was admitted to the renal service due to the brain trauma's changes in the hormones secreted from the brain, namely ADH (Antidiuretic Hormone) which has a significant effect on urine production and fluid balance, and blood pressure. Morphine dosing is simply for pain management, but she will likely be weaned from it soon.

She should have been examined for head injury by a specialist (a neurologist? neurosurgeon?). She must have renal complications to be transfered to the renal ward although it dose not make sense. I cannot figure out why shi is getting increased dosde of morphine unless she is having pain from injury. She should be examined and treated for head trauma first.

This question has to be addressed by your mom's admitting physician.

I'm sorry to hear this. I would be concerned too. Patients often get admitted to wards where this is an open bed as the proper ward is full, but that sounds like the least of her problems.
Find out who the physician is responsible for her care by calling the admissions department and contact the physician directly. Find out the treatment plan. Also find out who the registered "contact person" is, usually a family member that the hospital has on your mom's record. Often, the hospital will only communicate with that person due to privacy laws. My opinion is that often, privacy laws are an obstacle to patient care and family communications. 
Best wishes.

Hard to know without all the details, but beds sometimes are limited and patients are placed in whatever ward is available.