dear, cannabis an harm your brain and increase risk of developing insanity. Studies report that cannabis smoking or consumption in any from risks individual for development of psychotic disorder by 10 fold. In your case, yes there is definitely an exposure to your child in form of passive inhalation, although considering his developing and tender age the risk involved here could be substantial. A smoke free environment will definitely benefit him or her. hope to have satisfied your query. thank you. stay healthy.