At what age did you let your little one start to sleep with a lovey or security blanket? DD is 4.5 months and I have the a&a security blankets for her. She has just recently started to soothe herself by sucking on her thumb and a little part of the silk on the blanket. I'm torn, its the only way she self sootnes because she doesnt use a paci, but im still nervous to leave it in her crib.