Not necessarily. It can be suggestive, but can also be friendly.

I think it's really what is socially acceptable. It may seem more acceptable for the mother to spoon the children than it would be for the father to spoon children. I don't think it's acceptable for aunt's/uncles to spoon with children, or really any adult-children to spoon.

I think same-age spooning is most appropriate. I do think spooning as more sexual in nature, it's just another form of cuddling.