Have you spoken to her about this? If you have and nothing has changed I would change asap. your son should not be afraid. I have a son who is rough like the boy you describe, and he is learning by time outs that he cannot hurt others. My son has an extremely high pain tolerance and he has a hard time understanding what he does hurts others, because the same thing does not hurt him. But he has to learn, and if that little boy is not learning it is not a safe place for your son. My son is 4 now and has learned pretty well he can't do that to people. It has only happened a few times at pre-school over the last two years. So yes, hire a nanny. You can sometimes find them cheaper. My daughter has a severe peanut allergy(airborne and contact as well as ingestion), so I understand the allergy and she also has a mitochondrial disorder and ketotic hypoglycemia, so I also understand the precautions about illness. And yes, your best bet would be to hire a nanny to come to your home, or find one that will watch him in their home if you can be assured there will be no problem with the allergy issue. After college I worked as a nanny for 3 years for a family, and I loved it. It was one little boy and I went to their house. I didn't get paid a huge amount, but it was great work. I loved it. I am sure you could find someone who loves kids that much and will work for a decent price.