Is it "bad" if my 19 month old goes to bed with a bottle full of just water?

I know that a milk bottle is awful for bedtime because it rots their teeth... but is it terribly wrong for my 19 month old to go to sleep with a bottle full of just water? I know in a perfect world, she would be able to lull herself to sleep on her own, but she has always had sleep troubles. So I am wondering if maybe I could continue this until she was old enough for me to explain it to her... maybe when she transitions to a big girl bed. We have tried to take it away and she cries hysterically. I would hate for her to go through so much trauma for a habit that I feel is my fault, not hers (I used to nurse her to sleep... I'm a first time mom and didn't know this wasn't a good idea!) She ONLY has her bottle at bedtimes and has no problem drinking from sippy cups. I just feel like I really don't know what the best thing to do is! Any advice is appreciated. Thanks :)