Dd is 13 months, and I've always given her water from a regular glass. I think I started giving her water around 7 months or so (around the time she started drinking it from the bath
). But I still really don't give her much (if it was summer I'd giver her more, I'm sure, but right now I really only giver her a little after meals), as she is tiny and I really feel it interferes with bm intake. Breastmilk is the most nutritionally dense food/liquid she gets and I really feel she still needs quite a lot.
I'm not a fan of sippy cups. She has a tendency to chew it up, and I just cringe at the idea of her ingesting that toxic plastic. I have given her a plastic cup from time to time, though, with just a bit of water, and she doesn't chew on the edge the way she does on the sippy spout. But that's just my dd, I don't know if other babies chew on their cups the same way she does.