Overnight Care For A Sweet Senior

My family is looking for some relief from caregiver burn out. My wonderful grandma is bed bound but still lives at home. She is 89 with Alzheimer's and Parkinson's disease. She has a home aid but we need someone to stay overnight (8 p.m. to 10am) when the aid is not available. We all pitch in to help cover the night shifts but require someone a minimum amount of four nights a month (thur, fri, sat, sun available). We are flexible! It does not require giving any medications or helping with daily personal care needs. Ideally, someone to reply to her if she wakes up, which is a rare occurrence.