Is there something about your child(ren) that brings a smile to your face?
I would say anytime I see Mya experiencing something new and seeing her joy or interest brings a smile to my face. But on the same token I have had many a times when it has brought a tear too. Most recently at Mya's First Dance Recital I could not keep it together.
For Sophia anytime someone thinks of her and send me a picture remembering her it brings a huge smile to my face. That is why I collect Sophia's name. It brings me peace.