It's unusual, I think, to see this very often done composition without visible fingernails on the child's hand. The reason, I think, is that the fragility of the smallness is more emphasised by the nails, which seem even more impossibly small than the fingers themselves. But this is a decent attempt - I think the composition could be more orthodox, and stronger - it is, after all, a very orthodox image - perhaps by having the adult hand enter frame from a less straight up and down direction. Your toning is good though, but I feel you'll suffer for having presented a well known idea without quite enough pop to it.