My 6 and 8 year old have welcomed our newborn baby with love and enthusiasm and want to spend all day carrying her around. Although I definitely don't think they would deliberately hurt her, I am insisting that they only hold her when sitting down and supervised (I am in the vicinity). I worry that they might carelessly be a bit rougher or clumsy with the baby. They are most upset with me but I have stuck to my guns. AIBU?