I can't give you advice but I can relate. my neighbors dog was around my kids from the time she was 8 months old. Boxer APBTx. My neighbor was moving and I took the dog in permanently at about 2 years old. The first night she was officially mine my 4 year old ran up to her when she was sleeping to say goodnight. The dog bit her on the cheek...no blood but still I was kinda shocked. I told my little one that she couldn't do that when the dog was sleeping. The next morning my little one jumped out of bed and said she was going to say good morning to the dog. The dog was asleep and my little one got right in her face and the dog bit her again. On the forehead...blood everywhere from just a little tooth mark. My heart sank as I realized I probably couldn't keep the dog. I knew it wasn't the dogs fault though. I didn't have the heart to give the dog away but I knew if it happened again that it would be on me....and my conscience. It never happened again but it easily could have. I was as vigilant as I could be but I think if I had to give advice it would be to let sleeping dogs lie. And 4 months seems so young to make a call. We all have bad days but the potential is there for harm...it always is. I would try to keep sleeping seperate from interaction.