Sounds like a pretty common dream. the monster chasing the dreamer while there's someone they must protect. She shouldn't be overly concerned. It's a common nightmare.
It sounds like something in your home or life is possessed by a demon. You need to get rid of that item or stop doing whatever it is that involves demonistic practices. Pray to Jehovah god about it. Ask him for help. If he helps you, maybe you should look further into things. I hope that helps.