first of all congratulations for breastfeeding this long! :) i nursed my son for 20 months (then he self weaned) and it was the best thing i ever did. so if you have any ligering doubts about weaning, just know off the top that if you dont want to, if you feel you and your daughter arent ready dont feel pressured to have to wean! :)
moving on!
once you make the decision to not use the bottle, just dont offer it. get rid of them, put them away, whatever you have to do. dont give in and use one, dont let her see one, just erase them. only offer her the sippy. sure she might be upset, but she will just figure out that its over you know ?
one thing that helped with my son when we started milk is to make it chocolate. dont worry, its more important that she get the milk than what kind of milk it is. also; if you are into soy milk almond milk or rice milk, go ahead and try those as well. they are actually healthier anyway (soy especially for women). dont overdo it; only give her milk at meals, water other times, juce at snacks or rare occasions as a treat. water water water! :)
dont worry about "filling her up" before bed; humans dont sleep well on a full stomach; the digestion wakes us up. so dont worry about that. its highly possible that she really is hungry at least once at night, especially during growth spurts. her stomach is only the size of her fist, and thats normal. it empties fast, so you should be sensitive to that. i used to put a sippy cup of water in bed with my son, but sometimes he would wake up and want to nurse at night, usually around 4 am. he stopped doing that between 15-17 months.
one thing; never (or stop) giving a bottle of milk in bed. only give her water in bed. its bad for her teeth, and causes a lot of other messes as well (especially if you want her off the bottle; just eliminate it)
sleep is not even going to be perfect. once you relax and expect things to be up and down, you will be happier and more laid back about her not sleeping. i did the same thing with my son; he woke up around 4, came into bed with me, nursed both of us back to sleep, and was there until we got up 7 8 or even 9. i never cried it out (theres research out there about how harmful it is, and i would rather err on the side of caution, especially when it makes me so uncomfortable; thats a red flag!!) i just always responded to my son treating him like a person with needs. he is one of those spirited types who wont accept substitutes for the real thing! LOL.
anyway, if you want to keep nursing, you can even just nurse at night, or before bed, and no other times. your body will adjust the supply to when and how much you are nursing. if it makes you and your daughter happy, and you dont mind, you can just keep it up as long as its comfortable for both of you. it lasts such a short time, its not a big deal. :) however, if you want to quit, just try cutting one session at a time, distract her with something else, singing, stories, bath time, whatever you've gotta do. sippy cup with water in bed at night, maybe even a soft toy or book or two to keep her occupied if she wakes. my son would sometimes wake up but stay in his bed (which was in our room) and look at books for quite a long time, sometimes even going back to sleep.
anywy, i hope something ive said helps. just do what feels best for you all! :)