Good advice.
This spring I went through the same thing with my lab. I was a little worried. He wouldn't swim. He would go in up to his belly but no further. Just be patient and maybe try places wiith gradually sloping shores. Everyone else has pretty much said all there is to say.
She'll come around. My dog is now 15 months and I can't keep him out of the water. At the lake he'll swim out to me when I am on my sailboard. I can't go anywhere on the water with him nearby.