A gift isn’t the answer. When these things take place we don’t want more gifts. Take time to write her a short note. It’s thoughtful and she realizes you took the time to write it, that means something. Don’t go with apology words, she wants to know that you understand how you hurt her. She needs to know you are truthfully sorry. A nice note spoken from the heart will be much better then any gift. Then follow this up by taking her out someplace nice, she just may end giving you something in return.