I do believe in extended breastfeeding! See nothing wrong with that. From reading Dr. Christophers teachings and books he always stated a child does not need milk past 18 months because they no longer can digests it. When certain teeth come in....then the acids, etc change in the stomache! They cannot break the milk down after this age! Fruit should be of most importance by this age. You may want MH to elaborate on that! I would think this mostly has to do with animals milk...not breastmilk. I see nothing wrong with extended breastfeeding and many mothers breastfeed for years. I just would not give milk of any other kind more than eighteen months.
Give her a little at night and see how she reacts to it! HAve you tried a paci at night? You could try that too if you think it's just for comfort. I think you are doing a great job but at some point....MAMA needs some rest. It's important!