My 17 month old son still gets a bottle of milk before nap and before bed while he watches a baby Einstein video(I usually put puffies or cheerios out too). Before nap I just say time for nite-nite and put him down. At bed time after his video and milk, he gets a bath and I just clean his teeth with a wash cloth, then its story time, and he goes right down, and sleeps a good 11-12 hours. I think it helps him sleep longer, I have tried just giving him a sippy cup, he doesn't cry for a bottle but doesn't really drink the milk. If she wants a bottle I don't see the big deal, the extra milk won't hurt her and you can clean her teeth after wards if your worried. If she drinks from a sippy even better, I say do what works, their little bodies need the extra food. You'll see they will go through stages where it seems they went the whole day on two bites of food, so when my son will eat something I usually give him as much and often as he wants, he isn't overweight so I figure he needs it.