Hi there. and Welcome to YT. omg, I would have been absolutely terrified
i am very glad your baby was not hurt. Your roomate is not going to do anything about her big dog. IMO, If it this were me, I would be looking for a new place to live. If you are the main person on the rental agreement, then you have more options here. If you share the rent agreement and are locked in a lease, then PLease Keep you baby separated at all times. the chances are too great for the big dog to severely injure your yorkie. I think you were very lucky this time, and the dog was "playing" However, yorkie's are fragile, and it does not take much for the to get hurt, or killed by anther dog.