Matilda is so attached to her bottle, DH & I gave a time frame of 3. We figure her life is about to change dramatically in a few weeks with a new sister that having her nightly bottle isn't bad. She went to 2 bottles for her nap & bed at around 22 months and now is having the one at night, the day time nap is a "cup of milk" sort of inbetween a bottle & cup.