Is it OK for a nursing rabbit to use a salt lick?

My rabbit had babies not long ago (a week) and she won't eat her food. Bunny food to be exact, but she will eat grass and organic foods like that (vegitables), I heard that bunny food has salt in it too, but she tries to waste it in any way she can, and we got a salt lick and I'm afraid to give it to her cause she probobly knows the salt might be something with making her milk. But, ants and other bugs did get in her last bag. Is that the problem?