Washington, April 27 : Madonna has topped a new poll of `Hardest Working Mothers in Showbusiness'.
The Queen of Pop, who is mum to adopted tot David Banda, three, Rocco, eight and 12 year old Lourdes, bagged 110 million dollars in 2008, putting her on top of America''s Forbes magazine's list.
The `Material Girl' hitmaker earned most of her money from her world tour as well as record sales and a string of endorsement deals, reports Contactmusic.