Seeing both names together reminds of a folk song sung by
June Tabor (among others probably) that includes 'Sweet
William' and 'Lady
Margaret'. =) I really love both of the names.
William is just so classy and the nickname
Billy is cute though I'd use
Will myself.
Margaret is great too. I love the nickname
Daisy for it (my grandmother's name) and
Meg and
Maggie are quite nice.
My favourite nickname for
Margaret would have to be Meggie though.