Hiring an Overseas Caregiver to work in the US Page - Nannies and nanny services for 20 years in Canada and the US, OptiMum Childcare and Nannies Ltd.
An American family may legally hire a US citizen, someone who has been lawfully admitted for permanent residence, or someone with a valid work permit.
Eligibility for lawful employment must be verified by the employer using form I-9 form.
http://www.state.gov/r/pa/ei/rls/dos/1718.htm