When to take the bottle away?

Kimberly

Wondering when is the right time to transition baby from bottle? She won't use a zippy cup but does drink out of a straw. She'll be 15 months on August 1st. I'm still breastfeeding so she does nurse as well. I'm worried I may be losing my milk for I don't get nearly as much as before so I want to be able to prepare her.