If looking for a good Woman's self Defense Instructor in Omaha, I would recommend speaking to Christy Stevens at Dek's Tae Kwon Do, she is a retired police officer and has been doing woman's self defense training classes for a long time with a lot of happy students. Not certain she is still at this school or what her schedule is for woman's self defense classes right now, but she usually does several seminars specifically on this subject every year.
Of course there is always the traditional get into classes and study over a long period of time that really is what is needed if you want to learn unarmed self defense, and there are lots of good instructors (of course there are also lots of bad instructors as well). There is even one or two that hang around here. But if in a tough situation a specific short seminar/class is better than nothing. But I would recommend continuing if there is an issue that a person needs to be prepared for, keeps you physically ready and brings more and better tools into the tool box.