Take your mother to a doctor or Ayurvedic practitioner, before starting any new medication or supplement like Sandhi Mitra Vati. This is particularly crucial for patients with pre existing conditions, like diabetes, and considering potential interactions or contraindications. 

Alcohol is supposed to be predisposing factor for gout. But it's not scientific proven that gout will only flare if you quit the alcohol.

Perhaps your backache is associated with nerve injury. I recommend that you see a neurologist for an accurate diagnosis and treatment. They will perform further tests and establish what is causing your pain.

Your mother appears to be suffering from arthritis for a long time. The pain in her arm may be caused by joint inflammation which indicates that it’s a nerve problem if she experiences discomfort in the stomach too. When people have arthritis, sometimes they undergo a situation where nerves get affected hence feeling pain in different body parts apart from those with affected joints. To minimize the pain she is going through she should do gentle exercises, use warm towels if possible, and get drugs prescribed by a physician. 

The cervical injury normally comes with pain in the neck region. The reasons behind this can be accidents, incorrect posture, or too much hard work. For relief, first, rest your neck, use ice packs, and take pain medication if your doctor prescribes it. However, ensuring you get a professional opinion is important if the pain does not go away.