Fiancee visas are granted for 90 days only, the sponsor will have to sign and affidavit so the newcomer will not depend on public aid.
The couple should get married within 90 days of arrival, and ... no he/she can not work during that time.
A work authorization will be granted after the marriage and the new spouse will be given with a conditional resident status after the sponsor apply for it.
The status condition will change after 2 years of the marriage and it will be confirmed by the inmigration and naturalization department.
