I am not trying to criticize you , but your first mistake was ever putting juice in a bottle. Most pedi's will tell you to never give juice in a bottle because its so bad for their teeth. My daughter had a hard time drinking from sippy cups at first but I still never gave her juice in a bottle. I had tried the straw cups when she was younger. She very rarely drank juice. When her first birthday came it was my goal to eliminate the bottle, so I started to mix milk and formula. I started with a higher portion of formula and less milk, then every few days the ratio would begin to change until it was all milk. By the time it was all milk, it was in a cup only. My rule was that formula in bottles, milk in cups. So she never got to have milk in a bottle. It went smoothly. No fuss over it and by 13 months, she was off the bottle completely. At bedtime, she got a sippy of water. My suggestion is to do something to the milk in her bottle to make it taste yucky, like really water it down or add lemon juice, ect. And the same time you offer her the yucky milk bottle, offer her a sippy cup of milk that tastes good. Keep it up and don't give in even if she cries or fusses. She is 13 months and she will adapt quickly. You want to do it now while she is younger, because as she gets older, the habit of bottles gets even more difficult to break.