Yes. This was a formal request, issued on August 27, as specified in the Stafford Act, formally requesting Federal assistance for storm affected areas in Louisiana. Jefferson, Lafourche, Plaquemines, St. Bernard, and St. Charles Parishes were previously declared disaster areas on August 23, 2005 per FEMA-1601-DR for Louisiana Tropical Storm Cindy. The State of Mississippi made a similar request the morning of August 28th. The President announced the declarations in a news conference on August 28th. The declaration by the President officially went into effect on August 29th. Formal notice was given to the Congress and the notice was entered into federal register per FEMA-1603-DR and FEMA-1604-DR on August 29th for Louisiana and Mississippi respectively. Certain counties in Florida (FEMA 1602, Aug. 28) and Alabama (FEMA 1605, Aug. 29) were also declared disaster areas eligible for federal assistance. Shortly thereafter, as has been widely reported, the Congress met in special session to immediately approve a supplemental appropriation to cover the costs of disaster relief operations.
Also note that certain counties in Alabama, Florida and Mississippi were declared disaster areas due to Hurricane Dennis on July 10, 2005.
I have been told by others (who understand this better than I) that all she requested was money, not really physical help with evacuation.