3 bottles a day?

Is it normal for babies to drop the 4th bottle? I have a feeling she is dropping that last bottle before bed and only want 3 sippys a day. Today I offered 6oz sippys all day. For breakfast and lunch she took the whole bottle each time. Then for dinner she took 5ozs then 1oz before bed. If I can get 6ozs in her at dinnertime she won't need that last bottle because she got 18ozs total today!!! Yay!