Working in Canada as a visitor?

I plan to visit a friend in Canada and help her after she delivers her baby in Dec 2011 but will I be able to apply for a WORK PERMIT WHILE I'M IN CANADA if she or anyone else wants me to continue to work as a live in nanny. Anyone knows an agency who can arrange a work permit for me. Normal procedure it will take approx 12-18mths to obtain a WP in Singapore. Please help as I'm desperate. Thank you!