Normally to K-1 visa directions are very clearly spelled out in the packet sent by the consulate. You can also access the packet and all of the forms through the consulate's website. She will need a medical exam and the directions for getting the medical exam should have been provided as part of the consulate packet. Some of the required forms vary from consulate to consulate as not all consulates use the DS-160 yet. Check out the instructions sent to your fiance in her packet or those available online through the consular website.