A wise friend once said to me: "Don't loan to your friends unless you are willing to risk losing the money - otherwise there is a big chance you will lose the friend."
I hope you aren't owed a lot of money, and that you don't need it desparately! S., I was single for a number of years, and had a lot of struggling single girlfriends. I've loaned friends money several times. One woman I actually loaned $3,500 and got every penny of it back. There are only two outstanding loans - a five year old debt for $450 from a woman who could easily pay me back now that she's remarried, and $650 from a woman who is chronically ill and will never be able to give me the money back. In both cases, I've written off the money. For whatever reason the first friend has conveniently forgotten the debt. The second friend is ashamed so I pretend I've forgotten the debt. If I raise it in either case, the friendship will suffer. I have decided the friendship is more important than the money.
You have to decide this for yourself. If you really feel you are being cheated and that sours the friendship for you anyway, then you have the option of small claims court. Call the Johnson County clerk and ask for directions to file a small claims court claim. They are usually require a very simple pleading - a half page explanation of who owes you what. I haven't done this in Kansas (recently moved from Arizona), but all states have a small claims court. You usually have to pay a very small filing fee ($15-20) and a process serving fee ($30-35), but you can get it back in addition to what is owed to you. Be sure to ask for these to be reimbursed to you in your pleading. I want to update this because Amelia said you can't get paid through small claims court unless someone is willing to pay you. She is right that someone who avoids paying might try to avoid paying a court award too. But if they won't pay you, there are collection options. You can take your court award and go the clerk of the court and "attach" their home or other possessions so that they cannot sell the possession without clearing your debt. Of course, they might have no possessions, or be years till they decide to pay up. You can turn your award over to a collection agency who will hound them, for a percentage of the debt. There are ways to threaten their credit record, etc. I'm not an expert, but there are other ways forcibly to collect. But none of this is pleasant.
Alternatively, there is a provision in your annual tax return that lets you write off bad debt, and you might want to write it off. While that's not wholey satisfying, you can at least use it to offset other taxes you owe, bringing down your tax debt. Yes, I'm a lawyer, but no, don't consider me an expert in tax law. Ask an accountant!
Unfortunately, if you do take her to small claims court, you will be putting the seal of death on your friendship. But perhaps she's already done that herself by failing to pay you back. Only you can decide.