My son is 17 months old, has 1 bottle during the day at nursery. He goes 4 days a week, quite honestly I use formula milk because he doesn’t like regular milk to drink and he refuses it but will eat yoghurts, cheese and have milk in his weetabix or porridge etc my son only cry’s for a bottle when he sees it otherwise he’s not fussed. So if the bottle isn’t bothering her and she’s not fussing for it then keep it but if you think she’s crying or fussing for the bottle at night and not the milk then change to a sippy cup and give it to her maybe 30 mins before bed, so maybe after bath or before bath. She doesn’t need to have a bottle during the night, if she wakes up for it give her water instead as usually they are just thirsty. In regards to her being lactose intolerant you can buy lactose free milk and cheese and also the calcium babies need you can get from food not just dairy. Lots of leafy veg and nuts have high levels of calcium so that’s fine as well if she can’t drink cows milk.
We’re dairy free due to my sons allergies. He’s just been moved off prescribed formula onto oat/soy milk. He also wakes about half the week for milk overnight. We started with the bedtime bottle into a draw cup similar to his nursery water bottle. He initially took a bit less but the best day was fine and no problems since. With the overnight bottle it was a few weeks later we swapped it. Just used that bedtime straw cup and replaced it. He hated it the first 2 night but just went back to sleep after getting upset it wasn’t a bottle. We threw our bottles away so we could go back to them in the dead of night for easiness Now he’ll take it if he wakes, a small amount of oat milk but I do too it up with water. His sleep has seen a improvement, unsure if he was using the bottle for comfort but he sleeps through half the week now unsure if it’s a coincidence but definitely worked for us. Expect a tantrum or two if he’s attached to the bottle but stay strong you will be okay.