On days when my 4.5yo is not at nursery I let her watch tv downstairs whilst I put 6mo in her cot for a nap upstairs. Often putting baby down involves a feed and cuddle, so sometimes I'm gone for ten minutes. I leave the bedroom and living room doors open, so I can hear if 4 yo calls. She's a sensible girl, she knows to come to me if she needs something.
I wondered whether aibu to do this though? What age can children be safely left in a different room to play/watch tv by themselves?