Try to wake her up? Barney Stinson: Challenge accepted."
The duck can't help it and be Clumsy's pillow, that is so cute.^^
Grumpy looking happy at a sleeping Clumsy is something we really needed, seeing that Grumpy really loves the protagonist, and not being grumpy about her sleeping too much. Not to mention it looks very beautiful when Grumpy smiles.
And to answer the question: Clumsy is Grumpy's baby.