The ITIN application (w-7) is to be submitted when you file the tax return and she should be on the tax return. The CAA will verify the original identification document(usually it is a passport that satisfies the requirement) and mail it to ITIN operations at Austin along with the tax return. You can search for a CAA in your area on the IRS website.
The other alternative is to make an appointment with IRS office in your area and show them the original documents along with the tax return. They will verify the original documents and return them to you. They will send it to ITIN operations Austin for allotting an ITIN.
