A friend wants to know if she stepped on a nail and didnt get cut and it didnt go in her foot if she still needs a tetanus shot?

No: The skin must be punctured completely to force the clostridium tetani bacteria through to underlying tissues order to cause tetanus. A scrape won't introduce it, as well. If you do get a skin puncture, try to make the wound bleed to help get rid of any foreign matter that might have been introduced. If it is red and painful the next day, seek immediate treatment, even after your booster.