It is not a sin to prefer praying alone in a room if this is best for your heart. What is not permissible is to designate a place in the house that is considered to be a place of prayer and no one can use it for anything else and at the same time, you refuse to pray anywhere except in that place. Some even go to the extreme not to pray with the lights on. This is all no part of Islam.

Is it haram to prefer praying alone(im a female) and I prefer to pray in a room alone without people walking past or in the room?