she wants to let it die, she is throwing it out because it is sick and she does not want her other babies sick. baby bunnies have no way of surviving with human intervention until at least 2 months of age. otherwise your choice is to take it to be pts at a vet's office. this is natures natural selection and something is wrong with this baby.
"For every animal that dies in a shelter, there is someone somewhere responsible for its death".