I am taking my daughter to rehab today. She will be in Rehab for months. She has a four year old son who is very perceptive. During rehab we will be visiting our daughter, with our grandson. What should we tell him as to why she is there? Our daughter hasn;t been around much the last 5 months, our grandson does chastise her when they have spoken. Don't know what to say, don't want to tell him it is for drugs as who knows what he will say at his pre-k.