N.B.
First of all, you are doing a great job with your child. She benefits a lot from your breast milk.
As for your request, I can say that personally I nursed my son for 14 mo. I intentionally stopped feeding him and did it gradually, one session away in a couple of days or so. He was not yet able to fully communicate his wishes about nursing at that age. At the point when toddlers understand the whole process, it is difficult to "negotiate" a break. So, you will face some obstacles.
My friend who nursed her son for 2 1/2 y. did negotiate by giving him a reason to stop. He agreed. Or something that would work as a bargain point. You may try these strategies.
Good luck!