Aging parents

My mom lives alone and my sister and I both live several hours from her. She is in her 60’s and we sometimes worry when we don’t hear from her for a while. Everything is always fine, but we feel so helpless when she doesn’t respond to us for a whole night. I know she is an adult and needs her privacy, but we are looking for a way to check in on her too. Any ideas? Anyone dealing with something similar?