E.W.
I agree with PP, think about just nursing the one time a day. I BF my youngest son till he was 17 mos. old. When he was that age he just dropped it on his own with my substituting whole milk, mixed with a couple tbs. of cereal he drank straight from a cup. He was ready at that point. If there isn't some immediate reason to wean, consider waiting on dropping that last feeding and most likely she will drop it when she is ready, in the mean time you can try every now and then.