I bought this a few months early because I wasn't sure of size. . I got an xs because according to the messarments she would fit either an xxs or xs. glad I went with the xs. it fits her good, i kind of feel the neck is a little tight, but would rather it a bit tight than to loose. I like that it has a hook on the top to hook a lead to her so if she falls off my raft, and i can't get her right a way, I can pull on the lead and bring her to me. it reflects great as well. Not that she'll be wearinSee full review