I have been packing a recycled bottle from GT Dave’s Kombucha and keep it in a Built NY neoprene bottle holder called the Thirsty Tote. I’ve found something a little smaller and lighter for a child’s lunch (and for my purse) — the 9 oz. child’s bottle from Life Factory. The lid is #5 plastic and BPA-free and the bottle is glass (my favorite!) and it comes wrapped in a silicone sleeve. There are many different sizes available, from baby bottles, to large adult-sized bottles.
I found it yesterday at Elm Health on 7th Avenue, just below 14th Street (which is a clean, nice, well-stocked health food store and drug store with friendly, helpful staff). It was $14.99 at Elm, and is $12.99 on the website (but you have to pay shipping).